BMR Calculator
Estimate your basal metabolic rate using the Mifflin-St Jeor formula. Free online BMR Calculator for health — instant, accurate results, no signup needed.
Derivation
- ├── 01Given
w = 70, h = 175, age = 30, sex = male - ├── 02Formula
10 × e.w+6.25 × e.h-5 × e.age+("male"===e.sex?5:-161) - ├── 03Substitute
10 × e.70+6.25 × e.175-5 × e.30+("male"===e.'male'?5:-161) - └── 04Compute BMR (kcal/day)1,648.75
The Mifflin–St Jeor formula (1990) replaced Harris–Benedict (1919) because it is ~5% more accurate for modern body compositions.
Understanding the BMR Calculator
Basal Metabolic Rate (BMR) is the number of calories your body burns just to keep you alive — heartbeat, breathing, body temperature, brain activity — when you’re completely at rest. It’s the starting point for any calorie-budget plan.
Health metrics give us objective checkpoints against a body that can feel unreliable. Used alongside professional guidance — not in place of it — these numbers help you track progress and spot trends that matter. The BMR Calculator sits in that toolkit — it estimate your basal metabolic rate using the Mifflin-St Jeor formula. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.
How it’s calculated
Where
- BMR
- Calories burned per day at rest
- w
- Weight in kilograms
- h
- Height in centimeters
- a
- Age in years
- s
- +5 for men, −161 for women
Step-by-step walkthrough
A 30-year-old male, 70 kg, 175 cm tall.
- 0110 × 70 = 700
- 026.25 × 175 = 1,093.75
- 03−5 × 30 = −150
- 04Sum: 700 + 1,093.75 − 150 + 5 = 1,648.75
- 05BMR ≈ 1,649 kcal/day
Frequently asked questions
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