BMR Calculator
Calculate Basal Metabolic Rate and daily calorie needs by activity level
Your Details
Enter your details and click Calculate BMR
Basal Metabolic Rate (at rest)
— kcal/day
Calculated using the Mifflin-St Jeor formula
Daily Calorie Needs (TDEE) by Activity Level
| Activity Level | kcal/day |
|---|
How to Use
- Enter your Age, select Gender, and enter Height (cm) and Weight (kg).
- Click Calculate BMR to see your Basal Metabolic Rate.
- The results table shows your TDEE (Total Daily Energy Expenditure) across all 5 activity levels.
- Identify the row matching your lifestyle to find your daily calorie target for weight maintenance.
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to sustain vital functions — breathing, circulation, temperature regulation, and cell production. It represents the minimum energy your body needs to survive if you did nothing but lie still all day.
BMR vs TDEE vs Calories
| Term | Meaning | Use Case |
|---|---|---|
| BMR | Calories at complete rest | Baseline for all calculations |
| TDEE | BMR × activity multiplier | Daily calories to maintain weight |
| Deficit | TDEE − 500 kcal | Lose ~0.5 kg/week |
| Surplus | TDEE + 300–500 kcal | Build muscle / gain weight |
Mifflin-St Jeor Formula
Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
This is the most accurate formula for the general population, validated in multiple clinical studies.
Activity Multipliers
| Activity Level | Multiplier | Examples |
|---|---|---|
| Sedentary | × 1.2 | Desk job, little or no exercise |
| Lightly Active | × 1.375 | Light exercise 1–3 days/week |
| Moderately Active | × 1.55 | Moderate exercise 3–5 days/week |
| Very Active | × 1.725 | Hard exercise 6–7 days/week |
| Extra Active | × 1.9 | Very hard exercise + physical job |
Frequently Asked Questions
BMR (Basal Metabolic Rate) is the calories you burn at complete rest — breathing, circulation, and cell maintenance. TDEE (Total Daily Energy Expenditure) is BMR multiplied by your activity factor. TDEE is your actual daily calorie need to maintain weight. Eat less than TDEE to lose weight, more to gain.
BMR is a component of metabolism but not the whole picture. Metabolism includes BMR + thermic effect of food (digesting food burns ~10% of calories consumed) + exercise + non-exercise activity thermogenesis (NEAT — fidgeting, standing, walking). BMR typically accounts for 60–70% of total daily calorie burn.
BMR decreases with age at roughly 1–2% per decade after age 30. This happens because muscle mass naturally declines with age (sarcopenia), and muscle is metabolically more active than fat. Regular strength training is the most effective way to maintain BMR as you age.
Yes — build more muscle through resistance training. Muscle tissue burns ~6 kcal/kg/day vs fat's ~2 kcal/kg/day. Eating adequate protein also boosts the thermic effect of food. Crash diets lower BMR as the body adapts to reduced intake. Avoid eating below 1,200 kcal (women) or 1,500 kcal (men) for extended periods.