Retirement Calculator

What Is a Retirement Calculator?

Retirement planning compresses into two questions: what will I have, and what will it pay me? The first is compounding arithmetic on a savings rate and a timeline. The second is a withdrawal-rate judgment the profession has argued over since 1994. This tool answers both in one pass and shows its assumptions on both.

What the Tool Actually Models

Everything here happens in a single account with one return applied to every month. Your existing balance compounds from today to your retirement age. Each monthly contribution compounds from the month it lands, which means an early deposit does far more work than a late one. Nothing is withdrawn, no fee is deducted, and no tax is applied along the way.

That is deliberately narrow. There is no market data behind the projection, no forecast, and no opinion about what your portfolio will do — the return is a field you fill in, and the arithmetic is exact only about the consequences of your own assumption. The value of the exercise is not the last three digits of the answer; it is watching how much the answer moves when you change one input.

A useful reference point: set the return to 0% and the projection collapses to plain addition. Age 30 to 65 with $50,000 saved and $500 a month returns exactly $260,000 — the deposits, and nothing else. Every other result you see is that baseline plus compounding.

Nest Egg and Retirement Income Are Two Different Numbers

The headline is a balance: a single pile of money on your last working day. The second figure is a flow: what that pile could pay you every year without running dry. People conflate them constantly, and the gap between them is enormous — a $1,000,000 balance is a headline, while the income it supports under the 4% guideline is $40,000 a year, or $3,333 a month before tax.

Getting from balance to income requires an assumption about how long the money must last and how the portfolio behaves while you spend it. That assumption is where retirement planning gets genuinely difficult, and it is why the tool reports the income figure with a caveat attached to it rather than as a clean promise.

Read the two numbers in that order — balance first, income second — and the income figure is the one to argue with, because it is the one that determines whether you can stop working.

What a Retirement Target Looks Like in Portfolio Terms

The 4% guideline inverts into a rule of thumb people find easier to hold: multiply the annual income you want your portfolio to produce by 25. Wanting $40,000 a year from investments implies a $1,000,000 target; $60,000 implies $1,500,000; $80,000 implies $2,000,000. Choose a more cautious 3% withdrawal and the multiplier becomes 33 — $40,000 a year then needs $1,333,333.

The number that goes into the multiplication matters more than the multiplier. It is not your salary and not your current spending; it is the portion of retirement spending that your portfolio has to cover after Social Security, any pension, and any other income are subtracted. Households routinely target a balance far larger than they need because they multiply total spending instead.

If most of your saving happens inside an employer plan, project the match and the payroll deferral specifically with the 401k Calculator.

How Do You Calculate Your Retirement Savings?

Two standard formulas added together, then one multiplication. The first grows the money already sitting in the account. The second grows a stream of equal monthly deposits, each for the months it was actually invested. The third turns the total into income.

The Retirement Formula, Written Out

The whole projection is two lines, and the second one is where the argument lives:

Nest egg = C × (1 + r)ⁿ  +  PMT × [ (1 + r)ⁿ − 1 ] ÷ r

Income  = nest egg × 4%          (year one, inflation-adjusted after)

C   = current savings
PMT = monthly contribution
r   = assumed annual return ÷ 12, as a decimal   (7% → 0.07 ÷ 12 = 0.00583333)
n   = months until retirement                    (age 30 to 65 → 420)

The first term is plain compound growth on your opening balance. The second is the future value of an ordinary annuity — a finite geometric series with common ratio (1 + r), which is why 420 separate deposit calculations collapse into one compact fraction. "Ordinary" means each contribution lands at the end of its month, so the first $500 earns 419 months of growth rather than 420.

If the assumed return is 0%, the fraction would divide by zero, so the tool substitutes:

Nest egg = C + (PMT × n)

Note what the second line is not. It is not a projection of your account after retirement, and it does not model spending down the balance. It is one multiplication applied to the ending balance, and everything it assumes is covered further down this page.

Step by Step

Working a full run by hand — age 30 to 65, $50,000 already saved, $500 a month, 7% assumed:

• Count the months: (65 − 30) × 12 = 420.
• Convert the annual return to a monthly rate: 7 ÷ 1200 = 0.00583333.
• Compute the growth factor: 1.00583333 raised to the 420th power = 11.506152.
• Grow the existing balance: $50,000 × 11.506152 = $575,308.
• Grow the contributions: $500 × (11.506152 − 1) ÷ 0.00583333 = $900,527.
• Add the two halves: $575,308 + $900,527 = $1,475,835.
• Apply the withdrawal guideline: $1,475,835 × 0.04 = $59,033 a year.
• Divide for a monthly figure: $59,033 ÷ 12 = $4,919 a month, before tax.

The exponent has to be applied before anything is multiplied or subtracted, and the calculator rounds only at the end. Hand arithmetic that rounds the growth factor to three decimals early will land tens of dollars away — close enough to check your work, not close enough to quote.

Worked Example: Age 30 to 65

The two money fields load pre-filled at $50,000 and $500, so this run needs only the two ages and the rate typed in:

Inputs: age 30 · retire at 65 · $50,000 saved · $500/month · 7%/yr assumed

$1,475,835 at age 65 — 4% income ≈ $59,033/year ($4,919/month) before taxes

The decomposition is where this example earns its keep. The $50,000 grows to $575,308 on its own. The $500 a month grows to $900,527 on its own. The two halves are independent, so they simply add. Total money in over the 35 years is $260,000 — the opening balance plus 420 deposits of $500 — which means $1,215,835 of the result, or 82.4%, was added by compounding rather than by you.

Now look at the weighting. That $50,000 is 19.2% of every dollar you put in, but it produces 39.0% of the final balance. It has been compounding for the full 420 months while the average contribution has been invested for roughly half that. The same money is worth more the earlier it arrives, and that ratio — not willpower — is the entire argument for starting before you feel ready.

Using This Retirement Calculator Online

Five fields, no sign-up, no market data baked in. Two of them arrive pre-filled and three are yours to type, because a retirement projection with a hardcoded age is a projection of somebody else's life.

The Five Inputs

• Current Age — your age today, accepted from 15 to 80, though the retirement age has to be later than it and can go no higher than 80, so a current age of 80 always returns an instruction rather than a projection. Decimals count here: 79.9 still projects, over a tenth of a year. Decimals are accepted, so entering 30.5 runs a 34.5-year projection to age 65 and returns $1,422,279 instead of $1,475,835.
• Retirement Age — the age you plan to stop adding money and start drawing it. It must be later than your current age and no higher than 80.
• Current Savings ($) — everything already invested for retirement across accounts. Currency symbols and commas are stripped, so "$50,000" and "50000" both work. Enter 0 if you are starting from nothing.
• Monthly Contribution ($) — what goes in every month, the same amount month after month. Enter 0 for a projection of an existing balance left alone.
• Assumed Annual Return (%/yr) — your planning assumption, entered as a percentage. Type 7, not 0.07.

The two money fields are text inputs rather than number inputs on purpose: a number field rejects 0, and 0 is exactly what a balance-only or contributions-only plan needs in the other box. There is no field for your salary, your savings rate as a percentage, or your expected Social Security — the tool works in dollars per month, so convert before you type.

The Bounds the Tool Enforces

Four checks run before any math, and each returns a plain instruction where the balance would be:

• A current age below 15 or above 80 — "Enter your current age (15–80)".
• A retirement age at or before your current age, or above 80 — "Retirement age must be after your current age (up to 80)". The same message covers both mistakes.
• Both money fields at 0 — "Enter current savings, a monthly contribution, or both". With nothing invested there is nothing to project.
• A return below 0 or above 30 — "Enter an annual return between 0 and 30%". The ceiling is not a claim about what is achievable; past it a 35-year projection stops informing any decision. At the maximum 30%, the default plan returns $2,234,177,207, which is arithmetic rather than planning.

One quirk worth knowing: the money fields strip every character that is not a digit or a decimal point, so a minus sign silently disappears. Typing −500 as a monthly contribution is read as a $500 deposit. This tool models accumulation only and has no withdrawal mode.

What It Deliberately Leaves Out

There is no input for inflation, tax, fees, employer matching, Social Security, a pension, or a contribution that grows with your salary. Each of those was left out for the same reason: including it would require a figure that goes stale, a tax code that changes yearly, or a benefit estimate only your own statement can produce. A calculator that quietly assumes a 2026 contribution limit is wrong the following January and never tells you.

Every one of them can still be modeled here by adjusting what you type. Add your employer's match to the monthly contribution. Subtract fund and platform costs from the assumed return. Subtract expected inflation from the return to work in today's dollars. Then treat Social Security as a separate income stream added to the 4% figure at the end, rather than as part of the portfolio.

To pull a projected balance back into today's purchasing power without doing the exponent by hand, use the Inflation Calculator.

How to Read Your Result

The output is four lines, and each answers a different question — the balance, the assumptions behind it, the income it implies, and the reason not to treat that income as settled.

Line by Line

• "$1,475,835 at age 65" — the projected balance on the day contributions stop, in future dollars, before tax.
• "35 years of $500/mo on top of $50,000, at 7%/yr" — your inputs echoed back, so a screenshot is still interpretable a month later.
• "4% guideline income: ≈ $59,033/year ($4,919/month) before taxes" — the balance multiplied by 0.04, then divided by 12 for the monthly view.
• A closing caution that the 4% rule is a planning guideline from historical US portfolios, not a guarantee.

If the first line reads 0 and what follows is a sentence rather than an age, an input failed validation — read it as an instruction, not as a result.

Future Dollars, and How to Convert Them

The projection is nominal, so $1,475,835 in 35 years is not $1,475,835 of today's groceries. There are two defensible fixes, and they answer different questions:

• Deflate the answer. Divide by (1 + inflation) raised to the years. At 3% over 35 years the factor is 2.8139, which turns $1,475,835 into about $524,487 of today's purchasing power and the $59,033 income into roughly $20,979 a year — $1,748 a month. This assumes your $500 contribution stays $500 forever, losing real value every year.
• Run the tool at a real return instead. Subtract expected inflation from your nominal assumption — 7% minus about 3% gives 4% — and the same plan projects $659,154 with an income of $26,366. That figure is already in today's money, but it quietly assumes you raise your contribution with inflation each year.

Neither approach is wrong; they model different behavior, which is why they differ by more than $130,000 on the same inputs. The real error is mixing conventions — projecting a nominal balance and then comparing its income to what you spend this year.

The same trap catches the famous milestone. A $1,000,000 balance 35 years out is worth about $355,383 in today's money at 3% inflation. The million is a number, not a standard of living.

Judging Whether the Number Is Enough

Compare the income line to what you expect retirement to cost, not to your current salary. Subtract Social Security and any pension from projected spending first; what remains is the job the portfolio has to do. If the 4% figure covers it with room to spare, the plan has slack for a bad decade. If it covers it exactly, the plan has no slack at all, because the projection contains no volatility.

Three levers move the number, in descending order of reliability. Your monthly contribution is fully in your control and scales the result linearly — double it and the contribution half of the projection doubles exactly. Your retirement age is partly in your control and does three things at once: more deposits, more growth, and fewer years to fund. Your assumed return is not in your control at all, and raising it to make a plan work on screen changes nothing about the plan.

Run the plan you can actually execute at 5%, then at 7%, then at 9%. For the default inputs that spread is $854,732 to $2,624,061. A decision that still looks sound at the bottom of your range is a decision; one that only works at the top is a hope.

Retirement Chart: Saving Rate, Start Age and Income

Every row below is this calculator's own output. This first chart runs from age 30 to 65 at 7% with no starting balance, so the only variable is how much goes in each month.

The column that matters is the gap between the second and third. At every saving rate, compounding supplies 76.7% of the ending balance — the proportion never changes, because the annuity term is exactly linear in the contribution. Doubling what you save doubles the result and nothing else. There is no threshold you must clear before compounding starts working.

The Same $500 a Month, Started at Different Ages

Identical deposits, identical 7% assumption, identical retirement at 65. Only the start date moves.

Between 22 and 30 the saver skips $48,000 of deposits and loses $737,538 of balance. Between 45 and 55 the saver skips $60,000 — more money — and loses $173,921. A dollar skipped in the early band costs $15.37 of ending balance against $2.90 in the late band, so the same dollar does more than five times as much work at the start of the table as at the end, which is why a delay of a single year is expensive out of proportion to its cost: postponing from 30 to 31 skips $6,000 of deposits and costs $66,489.

What It Takes to Reach $1,000,000

Working backwards from the milestone. Each row is the monthly contribution that lands within a few hundred dollars of $1,000,000 by age 65, from a zero balance at 7%:

Read the third column rather than the second. Reaching the same milestone costs the 25-year-old $182,880 of their own money and the 55-year-old $693,360 — nearly four times as much cash for an identical outcome. And every row buys the same $40,000-a-year income in future dollars, which is worth less the further out it sits: deflated at 3% inflation, the 55-year-old's $40,000 is about $29,764 in today's terms after 10 years, the 30-year-old's about $14,215 after 35, and the 25-year-old's about $12,262 after 40.

The Same Plan at Different Assumed Returns

Age 30 to 65, $50,000 saved, $500 a month. Only the assumption changes; the deposits are identical in every row at $260,000.

One percentage point between 6% and 7% is worth $357,302 here; between 7% and 8% it is worth $485,734. Over 35 years the assumption drives more of the answer than the saving does, which is the strongest possible argument for subtracting fees before you type the rate. A single point of annual cost is the difference between two adjacent rows.

Retirement Examples

Six plans at different ages, balances and assumptions, each run through this calculator. The point of the table is the fourth column against the third — how much of each outcome the household actually paid for.

The first and last rows tell the whole story. The 25-year-old saving $300 a month ends with $787,444 having paid in $144,000. The 60-year-old with $600,000 already banked and $2,000 a month going in ends with $1,051,479 having committed $768,000. Time did most of the work in the first case and almost none in the last.

What One More Year of Work Is Worth

Take the default plan — age 30, $50,000, $500 a month, 7% — and move only the retirement age. Retiring at 64 projects $1,370,561; at 65, $1,475,835; at 66, $1,588,719; at 67, $1,709,764; at 70, $2,127,977. Each extra year near the end adds over $100,000 to the balance and roughly $4,500 a year to the income, on $6,000 of additional deposits.

From age 73 the IRS sets a floor under withdrawals whether you want the money or not, which can override any drawdown plan — size yours with the RMD Calculator.

The leverage is real but it is not free, and the calculator does not show the other half. Working to 70 instead of 65 raises the income figure by $26,086 a year while also removing five years the portfolio would have had to fund. That double effect is why retirement age is the most powerful lever available to a late starter — and why it is also the one that costs the most in life, not money.

Starting Late: What Actually Moves the Number

A 45-year-old saving $1,500 a month from a zero balance reaches $781,390 by 65 on $360,000 of deposits. A 30-year-old saving $500 reaches $900,527 on $210,000. The later starter has to reach about $1,750 a month — $911,622 — merely to draw level, having paid in $420,000 against the early starter's $210,000. That is the arithmetic behind every warning about delay, without the moralizing.

For anyone in that position the order of leverage is fixed. Raise the contribution first, because it is the only lever entirely in your control and it scales the result exactly. Extend the working years second. Capture every dollar of employer match third, since matched money is an immediate return no market assumption can compete with. Raising the assumed return to make the screen look better is the classic late-start error: it adds risk at precisely the age when there is no time to recover from it.

One structural help exists for this group. The IRS notes that "individuals who are age 50 or over at the end of the calendar year can make annual catch-up contributions" to plans including 401(k), 403(b) and governmental 457(b) accounts, with a higher limit again for those turning 60 through 63. The dollar figures change most years — check the current ones at the source, then enter the monthly equivalent here.

Retiring Early Breaks the Income Half

Nothing stops you setting the retirement age to 45. Age 30 with $50,000 and $3,000 a month at 7% projects $1,093,334 by 45, and the tool duly reports $43,733 a year at 4%. The balance is sound arithmetic. The income figure is not, because the 4% guideline was measured over 30-year retirements and a 45-year-old may be funding fifty.

The usual correction is a lower withdrawal rate: at 3.3% the same balance supports $36,080 a year rather than $43,733. Early retirement also removes access to Social Security for two decades and to penalty-free withdrawals from most tax-deferred accounts until 59½, neither of which this projection knows anything about.

The 4% Rule, and What It Assumes

The second half of this calculator rests on one number, and that number has a specific origin, a specific set of assumptions, and a known failure mode. All three are worth understanding before you plan around the income line.

Where the Number Came From

The guideline traces to William Bengen's 1994 paper in the Journal of Financial Planning, "Determining Withdrawal Rates Using Historical Data", which tested withdrawal rates against actual US market history rather than long-run averages. Bengen found that a first-year withdrawal of about 4%, increased with inflation each year afterward, survived every historical 30-year window in his data for a portfolio holding a substantial share of stocks. The Trinity study — Cooley, Hubbard and Walz, published in the AAII Journal in 1998 — reached broadly similar conclusions using success rates across stock and bond mixes, and it is the paper that made the phrase famous.

The mechanic is precise and often misquoted. You withdraw 4% of the balance once, in year one, and from then on you adjust that dollar amount for inflation. You do not recalculate 4% of the new balance each year. Recalculating annually is a different and much safer strategy, because it can never exhaust the portfolio — it simply cuts your income when markets fall.

So the $59,033 this tool reports for the default plan is a first-year figure. Year two would be that amount plus inflation, regardless of what the portfolio did in between. That is the rule as written, and it is the reason the rule can fail.

Sequence Risk: the Known Failure Mode

A fixed inflation-adjusted withdrawal is dangerous for one reason: the order of returns matters once money is leaving the account. Two portfolios that average the same return over 30 years produce completely different outcomes depending on when the bad years arrive. A severe loss in the first few years of retirement forces you to sell more shares to fund the same income, and those shares are not there to recover when the market does.

During accumulation the effect runs the other way and matters far less — this calculator's projection is unaffected by ordering because nothing is withdrawn. The SEC's Investor.gov puts the underlying volatility plainly: "Large company stocks as a group, have lost money on average about one out of every three years." A projection that applies exactly 7% to all 420 months contains none of that, by construction.

The practical consequence is that the income line deserves a wider margin than the balance line. The balance is arithmetic; the income is a bet on the thirty years that happen to follow your last day of work.

3.3% to 5%: the Honest Range

Practice has moved away from a fixed percentage toward spending that flexes with the portfolio. On the default $1,475,835 balance, the choice of rate is worth more than most people expect:

Income you can withdraw tax-free changes how large the balance has to be in the first place, which is the case for running the numbers in a Roth IRA Calculator.

The spread between the cautious and the flexible ends is $29,517 a year on the same pile of money — more than the difference many people would accept between two jobs. That is not an argument for either end. It is an argument for deciding, in advance, how much of your retirement spending you could actually cut in a bad year, because that answer is what sets your rate.

Limits: When This Projection Does Not Apply

Five places where the number on screen is not the number you will live with. None of them make the tool useless; all of them change how much weight the output deserves.

It Ignores Social Security, Pensions and Every Other Income

The income figure covers the investment leg only. For a great many US households Social Security is a comparably sized leg, and it arrives on its own schedule with its own rules — the CFPB's claiming tool notes that "waiting can increase your benefit from 30% less than full benefit, to 24% more," a swing this calculator cannot see. Your own benefit estimate comes from your Social Security statement, not from any projection.

Add your estimated benefit, any pension, rental income and expected part-time work to the 4% figure before judging whether a plan works. Subtract them from projected spending before deciding what the portfolio has to produce. Doing neither is the single most common way a retirement target ends up far too large.

No Tax, No Fees, No Contribution Limits

The projection is gross. A taxable brokerage account pays tax on dividends and realized gains along the way, so its effective compounding rate is below the headline assumption. Tax-deferred balances are pre-tax money — a traditional 401(k) worth $1,475,835 is not $1,475,835 of spendable income — while Roth balances broadly are. The calculator does not know which you hold.

Fees come out of the number you type, because there is no fee field. Take one percentage point off a 7% assumption and the default plan falls from $1,475,835 to $1,118,533: a $357,302 difference, on $260,000 of deposits, for a cost most savers never see debited. Nor is there any cap on contributions here — the IRS limits what can go into a 401(k) or IRA each year and revises the figures most years, so a monthly amount that projects beautifully may not be legally depositable into the account you had in mind.

Model all three the same way: lower the assumed return to approximate fees and tax drag, and check the current contribution limits at the source before committing to a monthly number.

Flat Contributions, Flat Returns

Every month gets the same deposit for the entire horizon, which no real career produces. Raises, bonuses, a pause for childcare, a house deposit that empties the account — none of it is modeled. If your contribution grows with income the projection understates the outcome, and by a lot: escalating that $500 by 3% a year lifts the default run from $1,475,835 to $1,848,892. If you stop for two years it overstates the outcome by more than the missed deposits, because those were the earliest dollars of whatever came next.

The workaround costs one extra run per change. Project the first phase, take its balance as the "current savings" of the second, and continue. It removes the least realistic assumption in the model without pretending the tool has fields it does not have.

Why Another Calculator Gives a Different Answer

Two conventions explain most of the gap. This tool compounds monthly and places each contribution at the end of its month. A calculator using beginning-of-month deposits multiplies the contribution term by (1 + r) and returns $1,481,088 on the default inputs — $5,253 more. One that compounds annually and takes a single $6,000 deposit each year returns $1,363,250, or $112,585 less.

Both gaps are small next to the difference between assuming 6% and 7%, which is $357,302 on the same plan. If two calculators disagree by a few percent, check the compounding convention. If they disagree by a third, check the return assumption — that is where the disagreement almost always lives.

The Hard Edges

Ages run from 15 to 80 and returns from 0% to 30%; anything outside those returns an instruction rather than a number, and the retirement age must be strictly later than the current age. There is no drawdown mode, no partial-year handling beyond decimals in the age fields, and no way to model a lump sum arriving mid-plan except by running the phases separately.

For the pure growth question without a retirement date attached — any horizon, any starting balance — the simpler tool is the Investment Calculator.

It also assumes contributions land at the end of each month and that compounding is monthly. Both are conventions, both are stated here, and both are worth knowing when a different tool hands you a different answer on identical inputs.