What Is TDEE?
Four processes spend calories, and TDEE is their sum. Your body burns energy to stay alive, to digest what you eat, to train deliberately, and to move incidentally through everything else in the day. A BMR equation measures only the first of those. The activity multiplier is shorthand for the other three, which is why the honesty of one dropdown decides most of the answer.
Basal metabolic rate is the floor — what your heart, brain, liver, and kidneys cost while you lie still and fasted. For most adults it is the single largest line on the page. For the reference man used throughout this article, a 30-year-old at 175 cm and 70 kg on Mifflin-St Jeor, that floor is 1,649 calories a day against a moderately active total of 2,556. Being alive accounts for 65 percent of what he burns.
The thermic effect of food is the energy spent digesting, absorbing, and storing meals; nutrition texts conventionally put it near 10 percent of intake. Exercise activity thermogenesis is the deliberate part, the sessions you would write in a log. Non-exercise activity thermogenesis — NEAT — is everything else: walking to the bus, standing, cooking, fidgeting. None of the three is calculated separately here. All three are bundled into the multiplier.
How Much of Your Burn Is Just Being Alive
Because BMR is fixed once you enter your body details, the share of your day it represents falls as the multiplier rises. These are the reference man's own figures at each of the six activity settings.
| Activity setting | TDEE (kcal/day) | BMR share of TDEE | Calories above BMR |
|---|---|---|---|
| Sedentary (1.2) | 1,979 | 83% | 330 |
| Light exercise (1.375) | 2,267 | 73% | 618 |
| Moderate exercise (1.55) | 2,556 | 65% | 907 |
| Hard exercise (1.725) | 2,844 | 58% | 1,195 |
| Physical job (1.9) | 3,133 | 53% | 1,484 |
| Professional athlete (2.0) | 3,298 | 50% | 1,649 |
At the top setting the multiplier doubles the floor, so exactly half of the estimate comes from activity the calculator never observed. That is the practical reason to be conservative: the higher you set the dropdown, the more of your result is assumption rather than arithmetic on your measurements.
Levine's review of NEAT adds a moving target to that assumption. NEAT rises when people overeat and falls when they undereat, so a multiplier that was honest in week one can quietly stop being true by week six of a diet — spontaneous movement drops without anyone deciding to move less.
TDEE vs BMR: What the Multiplier Pays For
BMR and TDEE are not competing estimates of the same thing; one is an input to the other. The reference man's BMR is 1,649 and his moderately active TDEE is 2,556, a gap of 907 calories. Every one of those 907 calories comes from the dropdown, not from his height, weight, age, or sex.
This matters when you compare numbers with someone else. If your friend quotes 1,500 and you quote 2,500, you may have near-identical bodies and simply be quoting different rows of the same calculation. Check which number each of you means before drawing any conclusion about metabolism.
If you want the resting figure on its own, with each equation shown separately rather than folded into a total, calculate it with the BMR Calculator.
How Do You Calculate TDEE?
Calculating TDEE is two steps: estimate resting metabolism from body measurements, then multiply. The first step is where the published research lives; the second is where your judgment lives.
TDEE = BMR × activity multiplier
The TDEE Formula, Written Out
With Mifflin-St Jeor selected — the default choice and the best-validated of the five — the whole calculation fits on three lines.
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161
TDEE = BMR × activity multiplier (1.2 to 2.0)
Both equations expect metric units. If you enter inches, feet, or pounds, the calculator converts before the equation runs — an inch becomes 2.54 cm and a pound becomes 0.453592 kg — so the arithmetic above is always what happens underneath.
The result is rounded to a whole calorie. Nothing else is rounded on the way, so a figure quoted here and a figure you get on screen will agree exactly.
The Five BMR Equations in the Dropdown
The first field changes which resting-metabolism equation runs. All five are published equations with different origins, different inputs, and different error behavior.
Run the same 30-year-old man, 175 cm and 70 kg, at the moderate multiplier through each one and the answers separate immediately.
Mifflin-St Jeor (1990) — men: 10 × weight + 6.25 × height − 5 × age + 5; women: 10 × weight + 6.25 × height − 5 × age − 161
Harris-Benedict (1918) — men: 66.5 + 13.75 × weight + 5.003 × height − 6.755 × age; women: 655.1 + 9.563 × weight + 1.850 × height − 4.676 × age
Revised Harris-Benedict (Roza and Shizgal, 1984) — men: 88.362 + 13.397 × weight + 4.799 × height − 5.677 × age; women: 447.593 + 9.247 × weight + 3.098 × height − 4.330 × age
Katch-McArdle — 370 + 21.6 × lean body mass (kg), where lean mass here is fixed at 80 percent of your weight
Schofield (1985), weight-only bands — men 18-30: 15.057 × weight + 692.2; men 31-60: 11.472 × weight + 873.1; men over 60: 11.711 × weight + 587.7
| Equation | BMR (kcal/day) | TDEE at 1.55 | Difference vs Mifflin-St Jeor |
|---|---|---|---|
| Mifflin-St Jeor (1990) | 1,649 | 2,556 | — |
| Harris-Benedict (1918) | 1,702 | 2,638 | +82 |
| Revised Harris-Benedict (1984) | 1,696 | 2,628 | +72 |
| Katch-McArdle (fixed 20% body fat) | 1,580 | 2,448 | −108 |
| Schofield (1985), weight only | 1,746 | 2,707 | +151 |
Pick Mifflin-St Jeor unless you have a specific reason not to. The 2005 systematic review by Frankenfield and colleagues compared the four equations dietitians actually use and found Mifflin-St Jeor predicted resting metabolic rate within 10 percent of measured values in more people — obese and non-obese alike — than Harris-Benedict, Owen, or WHO/FAO/UNU, with the narrowest error range of the group.
The 1918 Harris-Benedict equation runs high, and its authors' own data later said so: Mifflin's 1990 paper reported that Harris-Benedict overestimated measured resting energy expenditure by 5 percent. In this calculator that shows up as a 53-calorie higher BMR for the reference man, about 3 percent.
Step by Step
The form asks eight questions in a fixed order, and every one of them changes the answer except the two unit selectors, which only change how your entry is read.
The output is a single figure labeled TDEE (calories). There is no breakdown, no macro split, and no goal adjustment built into it — the number you see is maintenance, and every goal is something you do to that number afterward.
- Choose the BMR equation. Mifflin-St Jeor is the validated default.
- Choose male or female. The equations carry different constants for each — in Mifflin-St Jeor, +5 against −161.
- Enter age in whole years.
- Choose your height unit: cm, inch, or Feet.Inches.
- Enter height in the unit you just chose.
- Choose your weight unit: kg or pound.
- Enter weight in the unit you just chose.
- Choose the activity level that matches your typical week, not your best week.
Worked Example: 30-Year-Old Man, 175 cm, 70 kg
Mifflin-St Jeor, male, 30 years, 175 cm, 70 kg, moderate exercise 2-3 times a week.
BMR = (10 × 70) + (6.25 × 175) − (5 × 30) + 5
BMR = 700 + 1,093.75 − 150 + 5 = 1,648.75 kcal/day
TDEE = 1,648.75 × 1.55 = 2,555.56 → 2,556 kcal/day
- TDEE at the moderate setting
- 2,556 kcal/day
Over a week that is 17,892 calories. Change nothing but the dropdown and he gets 1,979 sedentary, 2,267 at light exercise, 2,844 at hard exercise, 3,133 with a physical job, and 3,298 as a professional athlete — a 1,319-calorie span across a single field.
Worked Example: 35-Year-Old Woman, 165 cm, 65 kg
Mifflin-St Jeor, female, 35 years, 165 cm, 65 kg, light exercise 1-2 times a week.
BMR = (10 × 65) + (6.25 × 165) − (5 × 35) − 161
BMR = 650 + 1,031.25 − 175 − 161 = 1,345.25 kcal/day
TDEE = 1,345.25 × 1.375 = 1,849.72 → 1,850 kcal/day
- TDEE at the light-exercise setting
- 1,850 kcal/day
Her figures across the same six settings are 1,614, 1,850, 2,085, 2,321, 2,556, and 2,691. Note the coincidence in that row: at the physical-job multiplier she lands on 2,556, the identical figure the reference man gets at moderate exercise. Two people with different bodies can share a maintenance number and need completely different weeks to justify it.
Entering Feet, Inches, and Pounds
The Feet.Inches option reads the digits after the decimal point as whole inches, not as a fraction of a foot. That is the single most common way to get a wrong answer out of this page.
Typing 5.1 when you meant five foot ten costs 222 calories a day. Keep the trailing zero, or switch the unit to cm or inch and avoid the question entirely. Inches above 11 are clamped rather than rolled over into another foot, so 5.12 does not become 6 ft 0 in.
| What you type | How it is read | Height used | TDEE (man, 30 y, 70 kg, 1.55) |
|---|---|---|---|
| 5.1 | 5 ft 1 in | 154.94 cm | 2,361 |
| 5.10 | 5 ft 10 in | 177.80 cm | 2,583 |
| 5.11 | 5 ft 11 in | 180.34 cm | 2,607 |
| 5.12 | clamped to 5 ft 11 in | 180.34 cm | 2,607 |
The weight unit has a quieter version of the same trap. Enter 154 while the selector still says kg and the reference man returns 3,858 instead of 2,553 — a 1,305-calorie error from one untouched dropdown. Check the unit selector before you trust a number that looks surprising.
Entered correctly, the units agree with each other. Feet.Inches 5.9 with 154 pounds returns 2,556, the same figure as 175 cm with 70 kg, because 5 ft 9 in is 175.26 cm and 154 lb is 69.85 kg.
TDEE Chart: Calories by Body and Activity Level
Every figure in this chart came from running the calculator on Mifflin-St Jeor. The four profiles are illustrative bodies, not population averages — find the row nearest your own build to see the range you are working inside before you enter anything.
Read across rather than down. The heavier 45-year-old man carries a BMR only 156 calories above the younger, lighter one, but at the athlete setting the two are 312 apart, because the multiplier scales the difference as well as the base.
| Profile | BMR | 1.2 | 1.375 | 1.55 | 1.725 | 1.9 | 2.0 |
|---|---|---|---|---|---|---|---|
| Man, 30 y, 175 cm, 70 kg | 1,649 | 1,979 | 2,267 | 2,556 | 2,844 | 3,133 | 3,298 |
| Man, 45 y, 180 cm, 90 kg | 1,805 | 2,166 | 2,482 | 2,798 | 3,114 | 3,430 | 3,610 |
| Woman, 30 y, 165 cm, 60 kg | 1,320 | 1,584 | 1,815 | 2,046 | 2,277 | 2,508 | 2,641 |
| Woman, 45 y, 170 cm, 75 kg | 1,427 | 1,712 | 1,961 | 2,211 | 2,461 | 2,710 | 2,853 |
What Each Activity Level Actually Means
The dropdown offers six settings. These are the descriptions attached to each, with what the reference man gets from choosing it.
One step is worth about 288 calories a day for this body — roughly a meal. Two people who describe the same week differently by one row will be handed maintenance numbers 288 apart, and if both eat to their number, one of them gains.
| Setting | Multiplier | Reference man's TDEE | Step up from the row above |
|---|---|---|---|
| Little or no exercise, sedentary lifestyle | 1.2 | 1,979 | — |
| Light exercise 1-2 times a week | 1.375 | 2,267 | +288 |
| Moderate exercise 2-3 times a week | 1.55 | 2,556 | +289 |
| Hard exercise 4-5 times a week | 1.725 | 2,844 | +288 |
| Physical job or hard exercise 6-7 times a week | 1.9 | 3,133 | +289 |
| Professional athlete | 2.0 | 3,298 | +165 |
The safer reading of these labels is the sedentary end. A desk job with three gym sessions is closer to light or moderate than to hard, because the multiplier is meant to cover the whole week, including the four days you did nothing. The athlete option is for people whose training is their occupation.
How Much Each Field Moves the Number
Changing one field at a time on the reference man, at the moderate multiplier, shows exactly what each measurement is worth.
At the moderate multiplier a kilogram is worth 15.5 calories a day, a centimeter 9.7, and a year of age 7.75. Forty years of aging costs this man 310 calories — barely more than one wrong click on the activity dropdown.
| Change | New TDEE | Difference |
|---|---|---|
| Weight 70 → 71 kg | 2,571 | +15 |
| Weight 70 → 75 kg | 2,633 | +77 |
| Weight 70 → 65 kg | 2,478 | −78 |
| Height 175 → 176 cm | 2,565 | +9 |
| Height 175 → 185 cm | 2,652 | +96 |
| Age 30 → 40 | 2,478 | −78 |
| Age 30 → 70 | 2,246 | −310 |
| Male → female, same body | 2,298 | −258 |
| Activity 1.55 → 1.725 | 2,844 | +288 |
That comparison is the point of the whole table. Measure your weight carefully by all means, but the field that decides your answer is the one you cannot measure at all.
Using the Free TDEE Calculator Online
The tool at the top of this page is free, needs no sign-in, and runs entirely in your browser — nothing you type is sent anywhere. It asks eight questions and returns one number.
Three fields open blank — age, height, and weight — so nothing is calculated until you fill them in and press Calculate. The other five start preselected on their first option: Mifflin-St Jeor, male, cm, kg, and the sedentary 1.2 multiplier. Change any of them and press Calculate again for the new figure.
- BMR Formula — Mifflin-St Jeor, Harris-Benedict, Revised Harris-Benedict, Katch-McArdle, or Schofield
- Gender — male or female
- Age — in years
- Height Unit — cm, inch, or Feet.Inches
- Height — in the unit selected
- Weight Unit — kg or pound
- Weight — in the unit selected
- Physical activity level (PAL) — six settings from 1.2 to 2.0
Run it more than once. Calculate at the multiplier you believe, then again one step either side, and you have the band your true maintenance level almost certainly sits inside — for the reference man, 2,267 to 2,844. A single figure invites false precision; a band tells you how much of it you actually know.
What the Calculator Does Not Ask For
Knowing what is missing is as useful as knowing what is included, because it tells you which claims about your result you can safely make.
The missing body-fat field matters most for one option. Selecting Katch-McArdle does not open a composition field; the equation runs on a fixed assumption of 20 percent body fat. That is why it returns 2,448 for the reference man and 2,448 for a woman of identical height and weight, and 2,448 whether you enter 175 cm or 190 cm, age 30 or age 65 — height, age, and sex do not appear in it at all.
- No body fat percentage field — nothing here measures or accepts composition
- No goal field — the tool returns maintenance only, never an adjusted target
- No macro split — protein, carbohydrate, and fat grams are a separate calculation
- No sleep, occupation, or step-count inputs — all of that lives inside the one multiplier
The published Katch-McArdle equation is driven entirely by lean mass, so a genuine 12 percent body fat would place that same 70 kg body near 2,636 and a genuine 30 percent near 2,214 — a 422-calorie band that a fixed assumption collapses to a single figure. Unless you are close to 20 percent, choose Mifflin-St Jeor instead.
Once you have a maintenance figure, turning it into grams of protein, carbohydrate, and fat is the next step, and that is what you get from the Macro Calculator.
How to Read Your TDEE Result
The number is calories per day at maintenance. It is not a target, a limit, or a score — it is the level at which your weight should hold steady if the estimate is right about you. Everything you do with it is arithmetic on that one line.
Eating Below It, At It, and Above It
The conventional planning figure is 3,500 calories per pound of body tissue, from Wishnofsky's 1958 paper. Applied to our two worked examples it gives this ladder.
The −1,000 row is in the table to complete the arithmetic, not as a recommendation. It puts the reference woman at 850 calories a day, far below any sensible unsupervised intake, and a deficit that large on a 1,850-calorie maintenance level is a 54 percent cut. A percentage deficit scales better than a flat one: 20 percent off gives the man 2,045 and the woman 1,480.
| Daily intake vs TDEE | Reference man (2,556) | Reference woman (1,850) | Conventional weekly change |
|---|---|---|---|
| −1,000 | 1,556 | 850 | about 2 lb (0.9 kg) lost |
| −750 | 1,806 | 1,100 | about 1.5 lb (0.7 kg) lost |
| −500 | 2,056 | 1,350 | about 1 lb (0.45 kg) lost |
| −250 | 2,306 | 1,600 | about 0.5 lb (0.23 kg) lost |
| Maintenance | 2,556 | 1,850 | steady |
| +250 | 2,806 | 2,100 | about 0.5 lb (0.23 kg) gained |
A surplus works the same way in reverse and should be smaller. Adding 250 calories is enough to support gaining lean weight without much of it being fat; adding 1,000 mostly adds fat, since the rate at which you can build muscle is not set by how much you eat.
For a deficit sized to a specific rate of loss and a target date rather than a round number, run the figure through the Calorie Deficit Calculator.
Recalculate as Your Weight Changes
A TDEE figure expires. Lose 5 kg and the reference man's maintenance drops from 2,556 to 2,478 — 78 calories gone — so the 2,056-calorie plan he started with is now only a 422-calorie deficit against 500. Re-entering the new weight rebuilds the plan at 1,978.
That drift is why long diets stall on paper before they stall in practice, and it compounds: every kilogram lost removes another 15.5 calories from the moderate-multiplier estimate. Recalculate every four to six weeks, after any change of about 4 to 5 kg, or whenever your training load changes.
The real effect is larger than the equation shows. Hall and colleagues modeled the full dynamics for The Lancet in 2011 and found body weight responds to a change in intake slowly, with a half-time of roughly one year, because expenditure adapts as you shrink. A static equation like this one cannot see that adaptation; only repeated recalculation approximates it.
Testing the Number Against the Scale
There is one way to find out whether your multiplier was honest, and it takes two to three weeks.
One step of the dropdown is about 288 calories for the reference man, so a full step is the right size of correction for a clear trend and too large for a wobble. Water weight moves a kilogram in either direction within a single day; two weeks of averages is the minimum that separates signal from noise.
- Eat at your calculated TDEE, weighed and logged, for 14 to 21 days.
- Weigh yourself at the same time each morning and use the weekly average, not any single day.
- Weight steady: the estimate was right. Keep it.
- Weight rising about 0.5 kg a week: you are roughly 500 calories over. Drop the multiplier one step.
- Weight falling about 0.5 kg a week: you are roughly 500 calories under. Move the multiplier one step up.
After that adjustment, your number is no longer an estimate from an equation. It is a measurement of you, which is the only version worth planning around.
Limits: Where a TDEE Estimate Breaks Down
This page returns a confident-looking whole number, and that confidence is not earned by the underlying method. Three separate sources of error stack up before you have eaten anything.
The Activity Multiplier Is a Guess
Nothing in the calculator verifies your activity. One step of the dropdown is 288 calories for the reference man and the full span from sedentary to athlete is 1,319 — larger than the effect of aging forty years, changing sex, and gaining 5 kg combined.
The ladder used here runs 1.2 to 2.0, extending the familiar Harris-Benedict-era convention that stopped at 1.9, and it does not match the physical activity level bands published by the FAO/WHO/UNU expert consultation, which classify a sedentary or light lifestyle as PAL 1.40 to 1.69, an active or moderately active one as 1.70 to 1.99, and a vigorous one as 2.00 to 2.40, with anything above 2.40 unsustainable over time. The 1.2 option sits below the floor of that published range: 1.40 is not one of the six settings, but applied to the reference man's basal rate it would return 2,308 calories a day, 329 above what the 1.2 setting gives him.
Neither scale is wrong, they simply define their categories differently. What follows from that is practical: do not compare a multiplier from this page against a PAL figure quoted from a nutrition guideline as though they mean the same thing.
Equation Choice Moves the Answer Too
The spread between the five equations is not constant. It is smallest for lean young bodies close to the populations the equations were derived on, and widest for the bodies furthest from them.
The 605-calorie spread on the last row is a warning, not a feature. It comes almost entirely from Katch-McArdle, whose fixed 20 percent body fat assumption is implausible for that body and inflates the estimate by 605 calories over Mifflin-St Jeor.
| Body, at 1.55 | Mifflin | Harris | Revised Harris | Katch | Schofield | Spread |
|---|---|---|---|---|---|---|
| Man, 30 y, 175 cm, 70 kg | 2,556 | 2,638 | 2,628 | 2,448 | 2,707 | 259 |
| Man, 55 y, 178 cm, 95 kg | 2,778 | 2,932 | 2,950 | 3,118 | 3,043 | 340 |
| Woman, 30 y, 165 cm, 60 kg | 2,046 | 2,160 | 2,145 | 2,181 | 2,132 | 135 |
| Woman, 55 y, 162 cm, 82 kg | 2,165 | 2,297 | 2,278 | 2,770 | 2,343 | 605 |
The Schofield option has its own blind spots: it uses weight only, so 150 cm, 175 cm, and 200 cm all return 2,707 for a 70 kg man, and it works in age bands rather than continuously. Crossing a band boundary produces a step change — 2,707 at age 30 becomes 2,598 at 31, and 2,598 at 60 becomes 2,182 at 61. A single birthday should not remove 416 calories from anyone's maintenance level, and physiologically it does not.
People the Equations Were Not Built For
All five are adult equations derived on specific populations, and the papers are candid about it.
Under 18, none of these applies, and the Schofield option behaves particularly badly: its age bands start at 18, so entering 16 silently routes the calculation into the over-60 equation and returns 2,182 for a 70 kg male — the identical figure a 65-year-old gets. Children and adolescents need age-specific equations this page does not carry.
- Mifflin-St Jeor came from 498 healthy adults aged 19 to 78 — 251 men and 247 women, 264 of normal weight and 234 with obesity.
- Harris-Benedict came from 239 normal subjects in 1918, and Roza and Shizgal's 1984 reevaluation put its precision at about ±14 percent in normally nourished people and called it unreliable in malnourished patients.
- Frankenfield's 2005 review noted that older adults and US-residing ethnic minorities were underrepresented both in deriving these equations and in validating them.
- Schofield's own paper reported that subjects from developing countries had lower metabolic rates per unit of body weight than European or North American subjects, and argued that individual-level prediction error must be high.
Pregnancy and breastfeeding add requirements no BMR equation includes. Thyroid disorders, fever, recent large weight loss, and many medications shift resting metabolism in ways the inputs cannot see. If any of those describes you, the number here is a rough anchor at best and a clinician's estimate is the one to use.
For scale, the NHS quotes 2,500 kcal a day for an average man and 2,000 for an average woman. Our reference man comes out at 1,979 when sedentary and 2,556 at moderate exercise; a 30-year-old woman at 165 cm and 60 kg comes out at 1,584 sedentary and 2,046 at moderate. Population averages and personal estimates can differ by 500 calories and both still be reasonable, because they answer different questions.
The 3,500-Calorie Rule Is a Convention, Not a Law
The arithmetic that turns a 500-calorie deficit into a pound a week traces to Wishnofsky in 1958 and assumes the tissue lost is entirely fat and that expenditure never changes. Neither assumption survives a long diet: some of the loss is lean tissue and water, and expenditure falls as body mass falls.
Expect the rule to hold reasonably for the first several weeks and to overestimate loss after that. The NIH Body Weight Planner models the adaptation properly and is the better tool for a long timeline; use this page for the starting level and that one for the trajectory.
None of this makes the estimate useless. It makes it a hypothesis. A TDEE figure you have eaten at for three weeks and corrected against your own scale is worth more than any equation's first answer, including this one's.