BMR Calculator (Basal Metabolic Rate)
Estimate how many calories your body uses at rest (BMR) and in a typical day given your activity level (TDEE), using the Mifflin–St Jeor equation.
Runs in your browser
How to use
- Choose sex and enter age, weight and height.
- Pick your activity level.
- Read your BMR and estimated daily needs.
How it works
The Mifflin–St Jeor equation (1990) is considered one of the most accurate predictive equations for healthy adults: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, or − 161 for women.
Daily needs (TDEE) multiply BMR by an activity factor from 1.2 (sedentary) to 1.9 (very active). Individual metabolism varies by around ±10%.
Examples
- Woman, 35, 65 kg, 168 cm
- BMR ≈ 1,364 kcal; lightly active ≈ 1,875 kcal/day.
Common uses
- Planning nutrition
- Understanding energy needs
Privacy & security
This tool runs entirely in your browser. Your files and text are never uploaded to our servers — processing happens on your device and results are created locally. How each tool handles files
Frequently asked questions
Is BMR the same as calories I should eat?
No. BMR is energy at complete rest; your daily needs include activity (TDEE).
How accurate is it?
For most healthy adults within about 10%. Medical conditions and body composition can change it.
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