BMR Calculator

Calculate your Basal Metabolic Rate (BMR) - the number of calories your body needs to maintain basic physiological functions at rest. Use this to plan your diet and fitness goals.

Personal Information

Gender

Age (years)

Height

Weight

Calculation Formula

Your BMR Results

Basal Metabolic Rate (BMR)

1649 calories/day

Using Mifflin-St Jeor

Daily Calorie Needs (TDEE)

Sedentary (little/no exercise)1979

Light activity (1-3 days/week)2267

Moderate activity (3-5 days/week)2556

Very active (6-7 days/week)2844

Extremely active (2x/day, intense)3133

Calorie Goals for Weight Management

Lose 2 lbs/week (-1000 cal/day)1556

Lose 1 lb/week (-500 cal/day)2056

Maintain weight2556

Gain 1 lb/week (+500 cal/day)3056

*Based on moderate activity level

BMR Breakdown

Per hour:69 calories

Per minute:1.1 calories

Per week:11541 calories

How BMR Calculation Works

Basal Metabolic Rate (BMR) represents the minimum number of calories your body needs to maintain basic physiological functions like breathing, circulation, cell production, and protein synthesis while at rest.

Mifflin-St Jeor

Men: 10 × weight + 6.25 × height - 5 × age + 5

Women: 10 × weight + 6.25 × height - 5 × age - 161

Most accurate for general population

Harris-Benedict

Men: 88.362 + 13.397 × weight + 4.799 × height - 5.677 × age

Women: 447.593 + 9.247 × weight + 3.098 × height - 4.330 × age

Traditional formula, slightly less accurate

Katch-McArdle

Formula: 370 + 21.6 × lean body mass

LBM: weight × (100 - body fat %) / 100

Most accurate for lean individuals

Understanding Your BMR

What Affects BMR?

• Age: BMR decreases with age (about 2% per decade after 30)
• Gender: Men typically have higher BMR than women
• Body composition: More muscle mass = higher BMR
• Genetics: Some people naturally have faster metabolism
• Hormones: Thyroid function significantly affects BMR
• Temperature: Cold environments can increase BMR

BMR vs TDEE

BMR (Basal Metabolic Rate)

Calories burned at complete rest

TDEE (Total Daily Energy Expenditure)

BMR + calories from daily activities and exercise

Example Calculation

30-year-old woman, 65kg, 165cm

Using Mifflin-St Jeor:

BMR = 10 × 65 + 6.25 × 165 - 5 × 30 - 161

BMR = 650 + 1031.25 - 150 - 161

BMR = 1,370 calories/day

Daily Needs (Moderate Activity):

TDEE = BMR × 1.55

TDEE = 1,370 × 1.55

TDEE = 2,124 calories/day

Frequently Asked Questions

How accurate are BMR calculations?

BMR calculations are estimates with about 10-15% margin of error. The Mifflin-St Jeor equation is considered most accurate for the general population. For precise measurements, indirect calorimetry testing is needed.

Can I increase my BMR?

Yes! Building muscle mass through strength training is the most effective way to increase BMR. Muscle tissue burns more calories at rest than fat tissue. Regular exercise, adequate protein intake, and staying hydrated also help.

Should I eat below my BMR to lose weight?

Generally no. Eating significantly below BMR can slow metabolism and lead to muscle loss. It's better to create a moderate deficit from your TDEE (total daily energy expenditure) for sustainable weight loss.