BMR Calculator for Weight Loss

Calculate BMR and TDEE for weight loss. Find your daily calorie deficit needed to lose 1-2 pounds per week using scientifically-backed formulas.

Calculate your Basal Metabolic Rate and daily calorie needs for effective weight loss using Mifflin-St Jeor and Harris-Benedict formulas.

About This Calculator

The BMR Calculator for Weight Loss helps you determine exactly how many calories you need to eat daily to achieve your weight loss goals. By calculating your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE), this tool provides personalized calorie targets based on the scientifically-validated Mifflin-St Jeor equation.

Understanding your BMR is the foundation of any successful weight loss plan. Your BMR represents the minimum calories your body needs to function at rest—powering essential processes like breathing, blood circulation, brain function, and cell repair. By knowing this baseline, you can calculate a safe calorie deficit that promotes fat loss while preserving muscle mass and metabolic health.

The Mifflin-St Jeor Formula

Men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5

Women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161

This formula, published in 1990, is considered the most accurate for estimating BMR in healthy adults and is recommended by the Academy of Nutrition and Dietetics.

Activity Level Multipliers (TDEE Calculation)

Activity Level	Description	Multiplier
Sedentary	Little or no exercise, desk job	BMR × 1.2
Lightly Active	Light exercise 1-3 days/week	BMR × 1.375
Moderately Active	Moderate exercise 3-5 days/week	BMR × 1.55
Very Active	Hard exercise 6-7 days/week	BMR × 1.725
Extra Active	Very hard exercise, physical job, 2x training	BMR × 1.9

Safe Calorie Deficit for Weight Loss

Weekly Goal	Daily Deficit	Recommendation
0.25 kg (0.5 lb)	275 calories	Best for minimal muscle loss, sustainable long-term
0.5 kg (1 lb)	550 calories	Recommended by most health organizations
0.75 kg (1.5 lb)	825 calories	Aggressive but achievable for overweight individuals
1 kg (2 lb)	1100 calories	Maximum recommended; may require medical supervision

Important: Never go below 1200 calories/day (women) or 1500 calories/day (men) without professional guidance. Extreme restriction can slow metabolism, cause muscle loss, and lead to nutrient deficiencies.

How to Use This BMR Calculator

Enter your age: Metabolism naturally decreases with age, affecting your BMR calculation.
Select your gender: Men typically have higher BMR due to greater muscle mass.
Input weight and height: The calculator supports both metric (kg/cm) and imperial (lbs/inches) units.
Choose activity level: Be honest—most people overestimate their activity level.
Set your weight loss goal: Start with 0.5 kg/week for sustainable results.

Common Weight Loss Mistakes to Avoid

Eating too little: Severe calorie restriction (under 1200) slows metabolism and triggers muscle breakdown for energy.
Not accounting for exercise: If you burn 300 calories exercising, you may need to eat those back to avoid excessive deficit.
Overestimating activity level: Choose the lower activity level if unsure; you can always adjust later.
Ignoring protein: Aim for 1.6-2.2g protein per kg body weight to preserve muscle during weight loss.
Expecting linear progress: Weight fluctuates due to water retention, hormones, and other factors. Track weekly averages.

Recommended Macronutrient Distribution for Weight Loss

Macronutrient	Percentage	Purpose
Protein	25-35%	Preserves muscle, increases satiety, highest thermic effect
Carbohydrates	35-45%	Energy for workouts, brain function, fiber for gut health
Fats	25-35%	Hormone production, vitamin absorption, sustained energy

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Ideal Weight Calculator — Find your target weight based on height and frame

Sources: Mifflin MD, et al. "A new predictive equation for resting energy expenditure in healthy individuals." Am J Clin Nutr. 1990. | World Health Organization (WHO) guidelines on healthy weight management. | Centers for Disease Control and Prevention (CDC) recommendations for safe weight loss (1-2 lbs/week). | Academy of Nutrition and Dietetics position on energy expenditure calculation methods.

Frequently Asked Questions

What is BMR and how is it calculated for weight loss?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production. The Mifflin-St Jeor formula calculates BMR as: Men: BMR = 10×weight(kg) + 6.25×height(cm) - 5×age + 5. Women: BMR = 10×weight(kg) + 6.25×height(cm) - 5×age - 161. For weight loss, you need to eat below your TDEE (BMR × activity multiplier) to create a calorie deficit.

How many calories should I eat to lose weight?

To lose weight safely, create a calorie deficit of 500-1000 calories per day below your TDEE. A 500-calorie daily deficit results in approximately 0.5 kg (1 lb) of weight loss per week, while a 1000-calorie deficit leads to about 1 kg (2 lbs) per week. Never eat below 1200 calories (women) or 1500 calories (men) without medical supervision, as this can slow metabolism and cause nutrient deficiencies.

What is the difference between BMR and TDEE?

BMR is calories burned at complete rest, while TDEE (Total Daily Energy Expenditure) includes all daily activities. TDEE = BMR × Activity Multiplier. Multipliers are: Sedentary (1.2), Light exercise (1.375), Moderate exercise (1.55), Active (1.725), Very Active (1.9). For example, if your BMR is 1600 and you exercise moderately, your TDEE is 1600 × 1.55 = 2480 calories.