Free BMR Calculator

Estimate your Basal Metabolic Rate — the calories your body burns at rest — using the widely used Mifflin-St Jeor equation.

Age

Weight (kg)

Height (cm)

Estimated BMR

1,780 kcal/day

Calories burned at rest. Multiply by an activity factor for your total daily needs. General estimate, not medical advice.

Estimate only. This tool is for general information only and is not medical advice or a diagnosis. Results are estimates based on the formula shown. Consult a qualified healthcare professional for guidance about your own situation.

Quick answer

Basal Metabolic Rate (BMR) is the number of calories your body uses at complete rest to keep functioning. The Mifflin-St Jeor formula estimates it as 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men, and the same with −161 instead of +5 for women.

Formula & method

Mifflin-St Jeor (men)

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

weight — body weight in kilograms
height — height in centimeters
age — age in years

Mifflin-St Jeor (women)

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Result is calories per day at rest. Multiply by an activity factor for daily needs (TDEE).

Examples

Example 1: 30-year-old man, 80 kg, 180 cm

Input: male, 80 kg, 180 cm, 30 yr
Result: ≈ 1,780 kcal/day
Why: 10×80 + 6.25×180 − 5×30 + 5 = 800 + 1125 − 150 + 5 = 1780.

Example 2: 30-year-old woman, 65 kg, 165 cm

Input: female, 65 kg, 165 cm, 30 yr
Result: ≈ 1,371 kcal/day
Why: 10×65 + 6.25×165 − 5×30 − 161 = 650 + 1031.25 − 150 − 161 = 1370.25.

Example 3: Imperial input

Input: 154 lb, 71 in, 30 yr (male)
Result: ≈ 1,780 kcal/day
Why: Converted to ~70 kg and ~180 cm, then run through the formula.

When to use this tool

Getting a baseline for daily calorie planning.
Understanding roughly how many calories you burn at rest.
As a starting point before applying an activity multiplier.

Common mistakes

Confusing BMR with daily calorie needs. BMR is at-rest only; multiply by an activity factor for TDEE.
Entering height in meters instead of centimeters.
Treating the estimate as exact. Individual metabolism varies by body composition and genetics.

Frequently asked questions

＋ What is BMR?

Basal Metabolic Rate is the energy, in calories, your body needs at complete rest to maintain vital functions like breathing and circulation.

＋ Which formula does this use?

The Mifflin-St Jeor equation, which is widely regarded as one of the more accurate estimates for most adults.

＋ How is BMR different from TDEE?

BMR is calories at rest. TDEE (total daily energy expenditure) multiplies BMR by an activity factor to include movement and exercise.

＋ Why do men and women have different formulas?

On average, body composition differs, so the equation uses a different constant (+5 for men, −161 for women) to reflect that.

＋ Is this medical advice?

No. It’s a general estimate for information only, not medical or nutritional advice. Consult a professional for personal guidance.

Disclaimer

This tool is for general information only and is not medical advice or a diagnosis. Results are estimates based on the formula shown. Consult a qualified healthcare professional for guidance about your own situation.

✓ Free to use
✓ No sign-up required
✓ Runs entirely in your browser — nothing is uploaded.
✓ Formula and method shown above

Last updated: 2026-06-05How we calculate Report a correction Disclaimer

Provided “as is” for general information only — results may be inaccurate, so verify before you rely on them. No warranty; use at your own risk.