BMR Calculator

What is BMR Calculator?

The BMR (Basal Metabolic Rate) Calculator estimates the minimum number of calories your body needs at complete rest to maintain vital functions like breathing, circulation, and cell repair. BMR accounts for 60–75% of total daily energy expenditure.

How to Calculate Basal Metabolic Rate (BMR)

1. Enter your age in years
2. Select your gender
3. Enter your weight in kilograms
4. Enter your height in centimetres
5. Click Calculate to see your BMR and daily calorie needs at different activity levels

How BMR Calculator is Calculated

Using the Mifflin-St Jeor formula (most accurate for adults): Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5. Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161.

Worked Example

For a 30-year-old male, 75 kg, 175 cm: BMR = (10 × 75) + (6.25 × 175) − (5 × 30) + 5 = 750 + 1093.75 − 150 + 5 = 1,699 calories/day at rest.

Common Use Cases

• Setting calorie targets for weight loss
• Understanding your base metabolism
• Nutrition and meal planning
• Fitness program design

Common Mistakes to Avoid

• Eating below your BMR to lose weight faster — consuming less than your BMR can slow metabolism, cause muscle loss, and lead to nutrient deficiency.
• Confusing BMR with TDEE — BMR is calories at rest only. TDEE includes daily activity and exercise, and is always higher than BMR.
• Not updating your BMR as your weight changes — recalculate after every 5 kg change for accurate calorie targets.
• Using the older Harris-Benedict equation instead of Mifflin-St Jeor — the latter is more accurate for modern populations.

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Why This Calculator Matters

Basal Metabolic Rate is the minimum calories your body burns at rest — just to keep you alive (breathing, circulation, cell production). BMR accounts for 60-75% of daily calorie expenditure. Knowing your BMR is the foundation for any weight management plan. The Mifflin-St Jeor equation (1990) is considered the most accurate for Indians.

What You Get

• BMR using Mifflin-St Jeor and Harris-Benedict equations
• Activity-level adjusted TDEE
• Macronutrient breakdown for goals
• Compare equations side by side
• Age and gender-specific calculations
• Calorie targets for weight loss/gain

How It's Calculated

Mifflin-St Jeor: Men: BMR = 10×weight(kg) + 6.25×height(cm) – 5×age – 5. Women: BMR = 10×weight(kg) + 6.25×height(cm) – 5×age – 161.

Real-World Example

Male, 30 years, 75 kg, 175 cm: BMR = 10(75) + 6.25(175) – 5(30) – 5 = 750 + 1093.75 – 150 – 5 = 1,688.75 calories/day. With moderate activity (×1.55): TDEE = 2,618 cal/day.

At a Glance

BMR and TDEE examples by age and gender

Practical Advice

• 💡 BMR decreases about 2% per decade after age 20 — adjust your intake as you age.
• 💡 Muscle mass increases BMR — strength training helps maintain metabolism.
• 💡 Crash diets below BMR cause metabolic adaptation, making future weight loss harder.
• 💡 Never eat below BMR for extended periods — it damages metabolism.
• 💡 Protein has a higher thermic effect (20-30%) than carbs (5-10%) or fat (0-3%).

Who Should Use This?

Anyone starting a weight management plan, fitness coaches designing meal plans, nutritionists, and athletes optimizing performance.