What your body burns at rest

Find out in seconds how many calories your body burns at rest (your basal metabolic rate, BMR) and how much you spend per day with your activity (your TDEE). We use the Mifflin-St Jeor formula, the most accurate per the evidence.

Basal metabolism estimated with the Mifflin-St Jeor formula (the most accurate per the evidence). Guidance, not medical advice.

Try it free

You have your target. Now the hard part

Hitting it daily. Photograph your plate and the app subtracts it from your target — no weighing, no searching.

Next time you sit down to eat, photograph the plate before the first bite. That is the whole method.

Try it with a photo

No install · result in 3 seconds

Or download the app

7 days free · No card · Private

What is basal metabolic rate and how is it calculated?

Your basal metabolic rate (BMR) is the energy your body spends just staying alive at complete rest: breathing, pumping blood, holding your temperature, running your organs. It accounts for roughly 60-70% of everything you burn in a day, which is why it is the base of any calorie target. We estimate it with the Mifflin-St Jeor equation, the most accurate of the widely used formulas: it takes your sex, age, height and weight. Multiply that BMR by an activity factor and you get your TDEE — total daily expenditure — which is the number you actually eat against. BMR is not something you eat at: it is the floor, and eating there for long stretches is neither necessary nor comfortable.

Basal metabolic rate by age and sex

What the body spends at rest, just staying alive. You can see the fall with age: about 50 kcal less per decade at the same weight and height. Much of that drop is not "a broken metabolism" but muscle that has been lost — and that part can be slowed down.

AgeMan 75 kg, 178 cmWoman 62 kg, 165 cm
251740 kcal1365 kcal
351690 kcal1315 kcal
451640 kcal1265 kcal
551590 kcal1215 kcal
651540 kcal1165 kcal

Computed with Mifflin-St Jeor, today considered more accurate than Harris-Benedict in the general population. These are reference ranges for healthy adults, not a diagnosis or individual advice.

FAQ

What is the difference between BMR and TDEE?

BMR is what you burn at complete rest; TDEE is what you burn across the whole day, including walking, fidgeting, digestion and exercise. TDEE is always the larger of the two, typically 1.2 to 1.9 times your BMR depending on how active you are.

Can you speed up your basal metabolism?

Modestly, yes. Gaining muscle raises it, because muscle tissue costs more at rest than fat does, and eating enough protein has a small thermic effect. What does not work is the supplement aisle: no pill moves your BMR in any way you would notice on a scale.

Why does my metabolism seem slower?

With age, and after losing weight, BMR does drop somewhat — less tissue to run, plus adaptation. Genetics play a part too. But most of what people read as a "slow metabolism" is a mismatch between what they think they eat and what they actually eat.

Is this formula accurate?

Mifflin-St Jeor is the most accurate of the popular equations, but it is still an estimate — expect around 10% either way for a given person. Use it as a starting point and let two or three weeks of real data tell you whether to adjust.

Keep reading