BMR Calculator
Calculate your basal metabolic rate — the calories your body burns at rest.
1,370 kcal/day
About this calculator
How This BMR Calculator Works
Enter your gender, age, height, and weight, and the calculator returns your Basal Metabolic Rate — the calories your body burns at complete rest just to keep vital functions running — along with estimated daily calorie needs at different activity levels.
Worked Example
A 30-year-old woman, 165 cm tall, weighing 65 kg, has a BMR of about 1,370 calories/day. At light activity, that scales up to roughly 1,884 calories/day of total daily energy expenditure; at very active, roughly 2,364.
The Formula
This calculator uses the Mifflin-St Jeor equation: for men, BMR = 10W + 6.25H − 5A + 5; for women, BMR = 10W + 6.25H − 5A − 161 — where W is weight in kg, H is height in cm, and A is age in years. It's widely considered more accurate for modern populations than the older Harris-Benedict equation.
From BMR to Daily Calorie Needs
BMR alone only covers calories burned at total rest — it doesn't include movement, exercise, or digestion. Multiplying BMR by an activity factor (roughly 1.2 for sedentary up to 1.725 for very active) estimates total daily energy expenditure, which is the number most people actually want when planning calorie intake for maintenance, loss, or gain. See the Calorie Calculator for a more detailed breakdown by goal.
Worked example
A 30-year-old woman at 165cm and 65kg has a BMR of about 1,370 kcal/day — the energy her body burns at complete rest, before any activity is added on top.
Frequently asked questions
What exactly is BMR?
Basal metabolic rate: the calories your body needs just to keep basic functions running — breathing, circulation, cell repair — while completely at rest. It's the floor, not your total daily burn.
How is this different from the Calorie Calculator?
This shows BMR on its own, plus a quick reference for common activity levels. The Calorie Calculator asks for your specific activity level up front and returns one tailored maintenance-calorie number.
Why does BMR decrease with age?
Muscle mass and metabolic activity tend to decline with age, and the Mifflin-St Jeor formula reflects that with an age term — all else equal, an older adult has a somewhat lower BMR than a younger one.