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BMR Calculator

Find your basal metabolic rate — the calories your body burns at complete rest — with this free BMR calculator. It uses the Mifflin-St Jeor equation and your sex, age, weight and height to give a resting metabolic rate, then shows your total daily calorie needs at every activity level. Everything runs privately, right in your browser.

Sex

Age (years)

Weight (kg)

Height (cm)

Activity level

Metric only. To convert imperial inputs: pounds ÷ 2.205 = kg, and inches × 2.54 = cm.

1,649 kcal/day

BMR by activity (total daily calorie needs)

Activity level	TDEE

What Is BMR?

Your basal metabolic rate is the calories your body burns at complete rest, before any movement, just to keep your heart, lungs, brain and organs working — often 60 to 70 percent of your daily burn. Resting metabolic rate is a near-identical figure, so the two terms are used interchangeably. This BMR calculator uses the Mifflin-St Jeor equation, the most widely trusted for healthy adults: men BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5, and women subtract 161. The older Harris-Benedict equation gives a similar but slightly less precise estimate for modern populations. Your BMR is the base; multiply it by an activity factor for your total daily energy expenditure (TDEE).

Who is this BMR calculator for?

This basal metabolic rate calculator estimates the energy you burn at rest using Mifflin-St Jeor. It is a starting point for anyone planning intake or setting a weight goal.

Weight loss: People setting a reduction goal use a bmr calculator for weight loss to set a safe calorie floor, then build a deficit from their TDEE.
Fitness: Lifters and anyone recomposing use a bmr calculator for fitness to set maintenance calories and plan a clean surplus or deficit.
Medical & dietitians: Clinicians use a basal metabolic rate calculator to estimate resting energy expenditure before tailoring a nutrition or recovery plan.
Athletes: Endurance and strength athletes use a bmr calculator for athletes to eat enough to fuel performance without overdoing it.

BMR chart and table — resting metabolic rate by age

Estimated BMR (kcal/day) using the Mifflin-St Jeor equation for a sample person at 70 kg and 175 cm. BMR falls with age as metabolism and muscle mass slowly decline, so a bmr table like this is a useful reference across the lifespan. General estimates, not medical advice.

Age	Men (70 kg, 175 cm)	Women (70 kg, 175 cm)
18	1,709	1,543
25	1,674	1,508
30	1,649	1,483
35	1,624	1,458
40	1,599	1,433
45	1,574	1,408
50	1,549	1,383
55	1,524	1,358
60	1,499	1,333
65	1,474	1,308
70	1,449	1,283
75	1,424	1,258
80	1,399	1,233

How to use this BMR calculator

Choose your sex.
Enter your age in years, your weight in kg and your height in cm. If you measure in pounds or inches, convert first using the note above.
Pick the activity level that best matches an average week.
Click Calculate BMR to see your resting metabolic rate.
Read the TDEE table to see your total daily calorie needs at each activity level.

Example

For a male aged 30, weighing 70 kg and standing 175 cm:

BMR = 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 700 + 1,093.75 − 150 + 5 = 1,648.75 ≈ 1,649 kcal/day.

If he is moderately active (multiplier 1.55), his total daily energy expenditure is about 1,649 × 1.55 = 2,556 kcal/day.

Common use cases

Setting a baseline daily calorie estimate before planning meals.
Understanding how much you burn at rest compared with through activity.
Losing weight without dropping below your resting metabolic rate.
Estimating maintenance calories for a fat-loss or lean-gain plan.

Pro tips

BMR falls roughly 1–2 percent per decade after young adulthood, so recheck your resting metabolic rate every few years.
The weight term dominates the formula — small changes to your weight move the result more than height or age.
When cutting, keep a few hundred calories above your BMR to protect muscle and keep your metabolism steady.
Treat any result as a starting point with a margin, not a strict prescription; adjust based on how your weight actually responds.

FAQ

What is BMR?

BMR stands for basal metabolic rate, the number of calories your body burns at complete rest to keep your heart, lungs, brain and organs functioning.

How is BMR calculated?

This calculator uses the Mifflin-St Jeor equation: for men BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5, and for women the same formula minus 161.

What is the difference between BMR and TDEE?

BMR is the energy your body uses at complete rest. TDEE adds activity, exercise and digestion, and is typically higher depending on how active you are.

What activity multipliers are used?

Sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725 and extra active 1.9. Each is multiplied by your BMR to give daily calories.

What is the Mifflin-St Jeor equation?

Mifflin-St Jeor is a widely used formula for predicting resting metabolic rate in healthy adults, considered more accurate for modern populations than the older Harris-Benedict equation.

What is resting metabolic rate (RMR)?

Resting metabolic rate is the energy your body stays alive on at rest, measured under slightly relaxed conditions. It is nearly identical to BMR, so the two terms are used interchangeably.

Is this BMR calculator accurate?

It is a strong estimate for most healthy adults using Mifflin-St Jeor, but it does not account for muscle mass, genetics or medical conditions, so treat the result as a guide.

Should I eat below my BMR to lose weight?

Avoid going far under your BMR long-term, as it can slow your metabolism. Create a modest deficit from your TDEE instead, usually 300–500 calories below maintenance.