BMR (Basal Metabolic Rate) Calculator
Compute Basal Metabolic Rate (BMR) — calories your body burns at rest — using Mifflin-St Jeor and Harris-Benedict formulas. Foundation for diet planning. Everything in your browser.
Mifflin-St Jeor
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Mais usada hoje em dia.
Harris-Benedict (revisada)
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Tendência a superestimar.
BMR: Basal Metabolic Rate
BMR (Basal Metabolic Rate) is how much energy your body burns at complete rest just to keep the lights on: heart beating, lungs working, brain ticking over, cells doing their housekeeping. These days the equation people trust most is Mifflin-St Jeor (1990). For men it's 10·kg + 6.25·cm − 5·age + 5 and for women 10·kg + 6.25·cm − 5·age − 161. The older Harris-Benedict (1919) runs a bit high, while Katch-McArdle works straight off lean mass (370 + 21.6·LBM_kg) once you know your body-fat percentage. Take a 75 kg, 175 cm, 30-year-old man: 10·75 + 6.25·175 − 5·30 + 5 comes out to 1,699 kcal/day. Multiply that by an activity factor somewhere between 1.2 and 1.9 and you land on your TDEE, the calories you need just to hold steady.
Applications and context
Pretty much every calorie target starts here. Want to lose fat? Eat 300–500 kcal under TDEE. Trying to add lean muscle without much fat? Bump it up 200–400 kcal. Happy where you are? Eat at TDEE. It's the same starting point for sports nutritionists, fitness apps like MyFitnessPal and Cronometer, and clinical dietitians, who then tweak the number for your goals, how much you train, and how you split your macros.
FAQ
BMR vs TDEE — what's the difference? BMR is what you burn lying still. TDEE piles on the rest: deliberate exercise, NEAT (the fidgeting and walking you don't think about), and the energy it takes to digest food. TDEE = BMR × activity factor.
Which equation should I use? For most people, Mifflin-St Jeor. Reach for Katch-McArdle only if you've got a solid body-fat reading from something like DEXA or a bod pod. It skips sex and age entirely, since your lean mass already accounts for them.
Can I eat below BMR to lose weight faster? It's a bad idea over the long haul. Your metabolism adapts downward, you start shedding muscle, and frankly you won't stick with it. The usual advice is a modest deficit below TDEE, not below BMR.
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Your basal metabolic rate (BMR)
Even lying down all day doing nothing, your body keeps burning energy just to keep its vital functions running. That minimum expenditure is the Basal Metabolic Rate, the BMR. Knowing it is the starting point of any diet, because it's from there that you work out how much to eat to lose, maintain or gain weight.
The calculator estimates your BMR with two well-established formulas, Mifflin-St Jeor and Harris-Benedict, starting from your basic data. Having both on hand gives a more reliable range than betting on a single number. From there, you just add the energy spent on physical activity to reach the daily total.
The calculation runs in the browser and none of your data is kept. Use it as a starting point, bearing in mind that every body is unique. For an eating plan tailored to you, a nutritionist's guidance makes a difference.