Estimate BMR and TDEE with the Mifflin-St Jeor equation to plan cutting or bulking calories
yrs
Enter a valid age (10-120)
cm
ft
in
Enter a valid height (metric 50-272cm / imperial 1-9ft)
kg
lb
Enter a valid weight (metric 10-500kg / imperial 20-1100lb)
Total Daily Energy Expenditure
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Fill in your details to calculate
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BMR
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Cut target (−500)
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Bulk target (+300)
BMR & TDEE Calculator — Complete Guide
Two numbers decide how many calories you should eat. Basal metabolic rate (BMR) is the energy your body burns simply to stay alive — breathing, circulating blood and holding its temperature at complete rest. Total daily energy expenditure (TDEE) is everything you burn across a whole day, so it is BMR scaled up by how active you are. Eat near your TDEE to maintain weight, below it to lose fat and above it to gain.
BMR versus TDEE
BMR is measured under strict laboratory conditions and is largely fixed by body size, age and sex — you cannot willpower it away. TDEE is the practical number for daily planning: it adds the calories spent walking, working, training and digesting food. TDEE is always higher than BMR, and the gap widens with activity.
TDEE = BMR × activity factor. Weight and height raise the estimate, age lowers it, and the constant differs by sex because men tend to carry more lean mass.
He maintains his weight at roughly 2,680 calories a day. A female example — 30 years, 165 cm, 60 kg — gives BMR = 10 × 60 + 6.25 × 165 − 5 × 30 − 161 ≈ 1320 kcal, and a TDEE of about 1,815 kcal on the light 1.375 factor.
Using the number well
Start from your TDEE, then adjust intake modestly and judge the result by the trend over two or three weeks, not day to day.
The estimate carries a margin of error of roughly ±10%; treat it as a starting point, not a fixed rule.
As you lose weight your BMR falls, so re-measure periodically to keep the target accurate.
Activity factors are broad averages — a "moderate" week can easily behave like a "light" one.
Protein and resistance training help protect lean mass, which keeps BMR higher during a fat-loss phase.
BMR is the calories your body burns at complete rest to stay alive. TDEE is your total daily burn including exercise and normal movement — it is BMR multiplied by an activity factor.
Which formula does this calculator use?
It uses the Mifflin-St Jeor equation, which is widely regarded as one of the most accurate for estimating resting energy needs in healthy adults.
How many calories should I eat to lose fat or gain muscle?
A common approach is to eat about 500 kcal below your TDEE to lose fat, or about 300 kcal above it to build muscle. Adjust gradually based on your results.