BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic life functions: breathing, circulation, organ function, and cell repair. It accounts for roughly 60 to 75 percent of total daily calorie burn for most people.

TDEE (Total Daily Energy Expenditure) is the total calories your body burns in a day including all physical activity. It is calculated by multiplying your BMR by an activity factor ranging from 1.2 (sedentary) to 1.9 (athlete). Eating at your TDEE maintains your current weight.

Which BMR formula is most accurate?

The Mifflin-St Jeor equation is considered the most accurate for general populations based on current research. It uses weight, height, age, and sex. The older Harris-Benedict equation tends to slightly overestimate BMR. Neither formula accounts for body composition (muscle mass), which is the main source of individual variation.

Why does my TDEE change when I lose weight?

As your body weight decreases, your BMR decreases too because there is less mass to maintain. This means your TDEE drops as you lose weight, and you may need to recalculate periodically. Recalculate every 5 to 10 kg of weight change for accurate numbers.

🔥 Mifflin-St Jeor Equation

BMR and TDEE Calculator

Q: How many calories should I eat to lose weight safely?

A safe, moderate deficit is 500 calories per day below your TDEE, which supports roughly 0.5 kg of weight loss per week. Avoid going below 1,200 calories per day for women or 1,500 for men, as very low intake can cause muscle loss and nutrient deficiencies. Rapid weight loss diets are not recommended.

Know how many calories your body actually burns per day. BMR is your resting baseline; TDEE includes all your activity. Use your TDEE as the starting point for any nutrition goal.

This TDEE calculator estimates your Total Daily Energy Expenditure, which is the total number of calories your body burns in a day. It first works out your Basal Metabolic Rate using the Mifflin-St Jeor equation, the formula dietitians consider the most accurate for the general population, then multiplies it by an activity factor based on how active you are. The result is a realistic daily calorie figure to build any nutrition plan around.

It is for anyone who wants to lose, maintain, or gain weight with intention rather than guesswork. If you have ever wondered how many calories you actually need, this is the number to start from. Students, office workers, parents, and gym-goers can all use it, because the activity levels range from mostly sedentary to hard daily training.

To act on your result, use your TDEE as your maintenance level, the calories that keep your weight steady. To lose weight, eat a few hundred calories below it. To gain, eat above it. Because these are population estimates, treat the figure as a starting point and adjust it after two to three weeks based on what the scale actually does. For a step by step walkthrough of the maths, read our guide on how to calculate your TDEE.

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⚚️ Health disclaimer: This calculator gives general estimates for educational purposes only. It is not medical advice and is not a substitute for guidance from a qualified doctor or dietitian. Results are based on general formulas and population averages, and individual needs vary. If you have any health concerns, or before changing your diet, exercise, or lifestyle, please speak with a healthcare professional.

How to Use This Calculator

Enter your stats

Age, gender, height, and weight are required. All inputs affect the Mifflin-St Jeor equation.

Select activity level

Be honest here. Most people overestimate activity. "Moderately active" means structured exercise 3 to 5 days per week.

Use TDEE for your goal

Eat at TDEE to maintain weight. Eat 300 to 500 calories below TDEE for gradual, healthy weight loss.

Frequently Asked Questions

What is BMR?

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest to maintain basic functions: breathing, circulation, organ function, and cell repair. It accounts for roughly 60 to 75 percent of total daily calorie burn.

What is TDEE?

TDEE (Total Daily Energy Expenditure) is the total calories your body burns in a day including all activity. It is your BMR multiplied by an activity factor. Eating at TDEE maintains your current weight.

How many calories should I eat to lose weight safely?

A safe, moderate deficit is 300 to 500 calories per day below your TDEE, supporting roughly 0.3 to 0.5 kg of weight loss per week. Avoid going below 1,200 calories per day for women or 1,500 for men. Very low calorie diets can cause muscle loss and nutrient deficiencies, and are not recommended without medical supervision.

Why does my TDEE change as I lose weight?

As your body weight decreases, your BMR decreases because there is less mass to maintain. Your TDEE drops as you lose weight. Recalculate every 5 to 10 kg of weight change to stay accurate.

Is TDEE accurate for me personally?

TDEE formulas are based on population averages and have an error margin of roughly 10 to 15 percent. If you are tracking food intake and not losing weight at a 500-calorie deficit, your actual TDEE may be lower than calculated. Track for 2 to 3 weeks and adjust based on real results.

What your TDEE number means

Your Total Daily Energy Expenditure (TDEE) is an estimate of how many calories your body uses in a day, including everything from breathing and digestion to walking and exercise. It is calculated from your basal metabolic rate, the energy you use at rest, often estimated with the Mifflin-St Jeor equation, multiplied by an activity factor that reflects how active you are.

TDEE is an estimate, not an exact figure. Activity, muscle mass, sleep, stress, and health conditions all shift your real needs, sometimes by a few hundred calories. Treat the number as a starting point for understanding roughly how much fuel your body needs, then adjust based on how you actually feel and function.

Using it well

Knowing your TDEE can help you eat enough as much as it can help you manage your weight. Eating far below your needs for long stretches can leave you tired, hungry, and run down, and very low intakes are not safe without medical supervision. If you are planning a meaningful change to how you eat or train, a doctor or dietitian can help you do it in a way that fits your body and goals.

Sources: Mifflin-St Jeor equation; general dietetic guidance.