Health

BMR Calculator

A BMR calculator using both the Mifflin–St Jeor and Harris–Benedict equations. Enter age, gender, weight, and height to see your resting calorie burn and TDEE across activity levels.

Gender Male Female

Age

Weight (kg)

Height (cm)

Basal Metabolic Rate

1,673 cal/day

Mifflin–St Jeor

1,673 cal

Harris–Benedict

1,724 cal

TDEE by activity level

Disclaimer. BMR calculators provide estimates based on statistical formulas. Individual metabolism varies. Consult a registered dietitian or physician for personalized nutrition plans.

Method

How this calculator works

BMR estimates resting energy expenditure using body metrics. The Mifflin–St Jeor equation is the most widely recommended for its accuracy in clinical and fitness settings.

Mifflin–St Jeor:
  Male:   BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5
  Female: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161

Harris–Benedict (revised):
  Male:   BMR = 88.362 + 13.397×weight + 4.799×height − 5.677×age
  Female: BMR = 447.593 + 9.247×weight + 3.098×height − 4.330×age

TDEE = BMR × Activity Factor

Select your gender.
Enter your age, weight (kg), and height (cm).
The calculator computes BMR using both Mifflin–St Jeor and Harris–Benedict equations.
TDEE is calculated for all five activity levels using BMR × multiplier.
Choose the activity level that matches your lifestyle to find your maintenance calories.

Examples

Worked examples

Real numbers, end-to-end results.

Male · 25 yrs · 70 kg · 175 cm

BMR 1,673 cal · TDEE 2,592 (moderate)

Average young adult male.

Female · 30 yrs · 60 kg · 165 cm

BMR 1,311 cal · TDEE 1,806 (light)

Female with light exercise routine.

Male · 40 yrs · 85 kg · 180 cm

BMR 1,793 cal · TDEE 3,090 (active)

Active middle-aged male.

Use cases

When to use it

Determine baseline calorie needs for weight loss or muscle gain.
Set accurate calorie targets in a meal plan.
Understand how aging and body composition affect metabolism.
Compare two popular equations side by side.

FAQ

Frequently asked questions

What is BMR (Basal Metabolic Rate)?

BMR is the number of calories your body burns at complete rest — just to keep organs functioning, breathing, and maintaining body temperature. It represents about 60–75% of total daily energy expenditure.

What is the difference between BMR and TDEE?

BMR is calories burned at rest. TDEE (Total Daily Energy Expenditure) adds your physical activity on top of BMR. TDEE = BMR × Activity Multiplier. TDEE is what matters for weight management.

Which BMR formula is more accurate?

The Mifflin–St Jeor equation (1990) is considered more accurate for modern populations than the Harris–Benedict equation (1919/1984). We show both so you can compare.

How do I use BMR for weight loss?

First calculate your TDEE (BMR × activity level). To lose weight, eat 300–500 calories below your TDEE. Never eat below your BMR as it can harm metabolism and health.

What factors affect BMR?

Age (decreases ~2% per decade after 20), muscle mass (more muscle = higher BMR), gender (males typically higher), genetics, thyroid function, and body size all influence BMR.

What are the activity level multipliers?

Sedentary (desk job, no exercise): ×1.2. Lightly active (1–3 days/week): ×1.375. Moderately active (3–5 days): ×1.55. Very active (6–7 days): ×1.725. Extra active (athlete): ×1.9.