BMR and TDEE calculator
Resting energy expenditure and total daily burn, worked out by three published equations side by side.
Basal metabolic rate is what you spend doing nothing at all; multiply it by an activity factor and you get total daily energy expenditure. This uses Mifflin‑St Jeor (1990) by default and shows the revised Harris‑Benedict and Katch‑McArdle beside it, so that a different figure elsewhere is explainable rather than mysterious. None of them is a measurement — they are regressions, and they miss by 100–200 kcal for individual people.
About you
What you enter is saved in this browser, so it is still here next time
Adds 5 in the Mifflin equation.
×1.375 — light movement 1–3 days a week.
From 1990, and the most widely used today.
Only needed for Katch‑McArdle. Leave at 0 if unknown.
What a day costs
Total daily burn (TDEE)
2,224 kcal
Resting burn (BMR)
1,618 kcal
How much the equations differ
- Mifflin‑St Jeor
- 1,618 kcal
- Harris‑Benedict
- 1,672 kcal
Calories by goal
| Goal | Weight per week | Per day |
|---|---|---|
| Lose 0.5kg | -0.5kg | 1,674 kcal |
| Lose 0.25kg | -0.25kg | 1,949 kcal |
| Maintain | 0kg | 2,224 kcal |
| Gain 0.25kg | +0.25kg | 2,499 kcal |
| Gain 0.5kg | +0.5kg | 2,774 kcal |
Goals assume 7,700 kcal per kilogram of body fat. Real weight change mixes water and lean tissue, so the timeline is always optimistic.
An estimate from published regression equations. Real metabolic rate varies between people and shifts with illness or medication. This is not medical advice.
Left at the defaults: a BMR of 1,618 kcal and 2,224 kcal a day
Put the defaults — male, 30, 170 cm, 70 kg — through Mifflin‑St Jeor and you get 10×70 + 6.25×170 − 5×30 + 5 = 1,617.5 kcal, which the screen rounds to 1,618. Multiplied by the 1.375 of the light activity level, total daily expenditure is 2,224 kcal. Age costs 5 kcal a year, but each activity step moves the figure by 283 kcal — sedentary gives 1,941 kcal and moderate 2,507 kcal, so one activity step outweighs thirty years of age.
Get a unit wrong and the answer is quietly wrong
Enter a height of 1.7 instead of centimetres and the BMR drops to 566 kcal; enter a weight of 154 straight from a scale in pounds and it becomes 2,458 kcal — and the screen stops neither. Body fat is used only by Katch‑McArdle, and choosing that equation with body fat left at 0 falls back to Mifflin‑St Jeor and says so.
Common questions
QI entered 20% body fat and nothing changed.
Because the equation is still Mifflin‑St Jeor. With the default body and 20% body fat, Katch‑McArdle gives 370 + 21.6×56 = 1,580 kcal, and a daily total of 2,172 kcal — 52 kcal below Mifflin.
QWhich equation should I use?
Without a body-fat figure, Mifflin‑St Jeor is the safe default: comparison studies since 1990 have generally found it the least wrong, and it is the most widely used today. If you know your body fat and carry a lot of muscle, Katch‑McArdle works from lean mass and drifts less. Harris‑Benedict is the 1919 equation as revised in 1984 — useful for comparing against older material.
QWhere do the goal calories come from?
From 7,700 kcal per kilogram of body fat, divided across the week. Losing 0.5 kg a week needs a deficit of 550 kcal a day (7,700 × 0.5 ÷ 7). Some calculators print 500 kcal for the same row; that is the imperial rule of 3,500 kcal per pound wearing a metric label, and it does not agree with the 7,700 figure printed beside it.
QHow do I pick an activity factor?
Most people belong one step lower than they think. Training three times a week while sitting the rest of the day is closer to 1.375. Overstating it inflates TDEE, which tells you to eat more, which moves you the wrong way. Watch two to four weeks of actual weight change and adjust by 100–200 kcal.