BMR & Calorie Calculator
Estimate the calories your body burns at rest and per day.
Sex
kg
cm
years
Activity level
2,556 kcal
Formula
Examples
| Input | Result |
|---|---|
| Man, 80 kg, 180 cm, 30 years | BMR 1780 cal/day; TDEE at moderate activity (x1.55) 2759 cal/day |
| Woman, 65 kg, 165 cm, 30 years | BMR 1370 cal/day; TDEE at light activity (x1.375) 1884 cal/day |
| Man, 80 kg, 180 cm, 30 years, sedentary (x1.2) | TDEE 2136 cal/day |
About this calculator
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest simply to stay alive, powering essentials such as breathing, circulation, brain activity and cell repair. It typically accounts for 60 to 70 percent of the calories you burn each day and is the foundation for working out how much you should eat to lose, maintain or gain weight.
This calculator uses the Mifflin-St Jeor equation, widely regarded as one of the most accurate predictive formulas. For men, BMR equals (10 times weight in kg) plus (6.25 times height in cm) minus (5 times age in years) plus 5. For women, the final constant is minus 161 instead of plus 5. To estimate total daily energy expenditure (TDEE), the calculator multiplies your BMR by an activity factor: about 1.2 for sedentary, 1.375 for light activity, 1.55 for moderate, 1.725 for very active and 1.9 for extremely active people.
To use it, select your sex, then enter your weight, height and age, and pick the activity level that best matches a typical week. The tool returns your BMR and your TDEE so you can see both your at-rest burn and your real-world maintenance calories.
Interpreting the output is simple: your BMR is the absolute minimum you should rarely eat below, while your TDEE is roughly the calories needed to keep your current weight steady. Eating about 500 calories below TDEE produces around 0.5 kg of fat loss per week; eating above it supports muscle gain.
A few cautions help accuracy. The activity multiplier is the biggest source of error, so be honest and avoid over-estimating. BMR predictions assume average body composition; very muscular or very lean people may burn more than the formula suggests. Recalculate every few kilograms of weight change, and treat the figures as a smart starting point you fine-tune by tracking real results over two to three weeks.
Frequently asked questions
BMR is the calories you burn at total rest just to keep your organs running. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor and represents everything you burn in a normal day, including movement, exercise and digestion. You eat around your TDEE to maintain weight, not your BMR.
Research has found Mifflin-St Jeor predicts resting metabolic rate more accurately than older equations like Harris-Benedict for most modern adults. It uses weight, height, age and sex and tends to be within about 10 percent of measured values for people of average body composition.
No. Eating at your BMR usually means a very large deficit once activity is added, which can slow metabolism and cost muscle. A safer approach is to eat about 300 to 500 calories below your TDEE so you lose roughly 0.25 to 0.5 kg per week while staying nourished.
Recalculate whenever your weight changes by about 3 to 5 kg, or if your activity level shifts significantly. BMR falls as you lose weight, so updating the figure prevents your deficit from quietly shrinking and stalling progress.
BMR depends on height, age and sex as well as weight. A taller, younger or male person generally has a higher BMR at the same weight. Muscle mass also raises BMR, which the formula cannot directly measure, so two people of identical stats can still differ.
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