What is BMR (Basal Metabolic Rate)?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep your organs functioning. It accounts for 60–75% of total daily calorie expenditure. Your TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor to account for movement and exercise.

How many calories do I need to lose 1 pound per week?

To lose 1 pound (0.45 kg) per week, you need a daily deficit of 500 calories. This is because 1 pound of body fat contains approximately 3,500 calories. A deficit of 250 calories per day results in about 0.5 pounds lost per week. Most health guidelines recommend no more than 1–2 pounds of weight loss per week.

What is the Mifflin-St Jeor equation?

The Mifflin-St Jeor equation calculates BMR based on weight, height, age, and sex. For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5. For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161. It is considered more accurate than the older Harris-Benedict equation.

Calorie Calculator

Find your daily calorie needs for weight loss, maintenance, or gain. Based on the Mifflin-St Jeor equation.

Units: Imperial (lbs, ft/in) Metric (kg, cm)

Age

Sex

Height (ft)

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Weight (lbs)

Activity level

Quick Answer

Most adults need 1,600–3,000 calories per day depending on size and activity. To lose 1 lb/week, eat 500 calories below your TDEE. To gain weight, eat 250–500 above. BMR is what you'd burn at rest — TDEE is BMR multiplied by your activity level.

How many calories do you need?

Your Total Daily Energy Expenditure (TDEE) is the total number of calories your body needs each day to maintain your current weight. It accounts for your basal metabolism (the calories you burn just existing) plus all the calories you burn through physical activity. To lose weight, eat less than your TDEE. To gain, eat more.

Calories and weight loss

One pound of body fat stores approximately 3,500 calories. A daily deficit of 500 calories results in roughly 1 lb of weight loss per week. This is a guideline, not a precise rule — factors like water retention, muscle gain, and metabolic adaptation affect actual results. Most health guidelines recommend a deficit no larger than 500–750 calories per day to preserve muscle mass.

About the Mifflin-St Jeor equation

This calculator uses the Mifflin-St Jeor equation, published in 1990. Multiple studies have found it to be more accurate than the older Harris-Benedict equation for estimating BMR in modern populations. It is the equation recommended by most registered dietitians. Results are estimates — individual metabolism varies by 10–15% from the calculated figure.

Medical note: These results are estimates for informational purposes only. For personalised nutrition advice or if you have a medical condition, consult a registered dietitian or your doctor.

Frequently asked questions

How many calories should I eat per day?

It depends on your age, sex, height, weight, and activity. Most adults need 1,600–3,000 calories. Use this calculator for a personalised estimate based on the Mifflin-St Jeor equation.

What is BMR?

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest to sustain basic functions. Your TDEE is BMR multiplied by your activity factor.

How many calories to lose 1 pound per week?

A daily deficit of 500 calories below your TDEE results in roughly 1 lb lost per week, since 1 lb of fat is approximately 3,500 calories.

What is TDEE?

TDEE (Total Daily Energy Expenditure) is the total calories you burn per day accounting for activity. It is your BMR multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (extremely active).