TDEE Calculator

TDEE is calculated in two steps. First, your Basal Metabolic Rate (BMR) is estimated — this is the number of calories your body needs at complete rest just to keep you alive (breathing, circulating blood, maintaining body temperature). Then your BMR is multiplied by an activity factor that reflects how much you move throughout the day.

This calculator uses the Mifflin-St Jeor equation, published in 1990 and validated by the American Dietetic Association as the most reliable BMR formula available:

Males: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5

Females: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161

An older alternative is the Harris-Benedict equation, originally developed in 1919 and revised in 1984 by Roza and Shizgal. While still widely cited, studies comparing the two formulas consistently find that Mifflin-St Jeor produces estimates closer to actual measured metabolic rates, particularly in overweight populations. The Harris-Benedict equation tends to overestimate BMR by about 5%, which can lead to eating more than intended.

Your BMR only tells you what you burn at rest. To get your actual daily calorie expenditure, it's multiplied by a factor that represents your physical activity. These multipliers were established through research on energy expenditure and are used in virtually every TDEE calculation:

Sedentary (1.2):Little or no exercise. You work a desk job and don't do much physical activity outside of normal daily movement. This applies to most office workers who don't have a regular exercise routine.

Lightly active (1.375): Light exercise or sports 1-3 days per week. This might mean a few casual gym sessions, regular walks, or an active commute.

Moderately active (1.55):Moderate exercise 3-5 days per week. You're consistently hitting the gym, running, cycling, or doing other structured exercise most days of the week.

Very active (1.725): Hard exercise 6-7 days per week. This level fits serious athletes, people training for competitive events, or those with physically demanding daily routines on top of regular workouts.

Extra active (1.9): Very hard exercise plus a physical job, or training twice per day. Think construction workers who also train, competitive athletes in heavy training blocks, or military personnel in active training.

A common mistake is overestimating your activity level. If you're unsure, start with one level lower than you think. You can always adjust upward if you're losing weight faster than expected.

BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure) are related but distinct measurements. Your BMR is the number of calories your body burns just to stay alive — if you lay in bed all day without moving, your body would still burn this many calories to maintain organ function, regulate temperature, and keep cells running. For most people, BMR accounts for roughly 60-75% of total daily calorie burn.

TDEE builds on BMR by adding three additional components: the thermic effect of food (TEF), which is the energy used to digest and process what you eat (about 10% of calorie intake); non-exercise activity thermogenesis (NEAT), which covers all the small movements you make throughout the day like walking, fidgeting, and standing; and exercise activity thermogenesis (EAT), which is the energy burned during intentional exercise.

You should never eat below your BMR for extended periods. Doing so can slow your metabolism, cause muscle loss, trigger nutrient deficiencies, and lead to hormonal disruption. A safe caloric deficit targets your TDEE minus 250-500 calories, keeping your intake well above your BMR.

Once you know your TDEE, managing your weight becomes a matter of simple arithmetic. To lose weight, eat fewer calories than your TDEE. To gain weight, eat more. The size of the deficit or surplus determines how fast you change.

A 500-calorie daily deficit creates a weekly deficit of 3,500 calories, which roughly translates to losing about one pound per week. A 250-calorie deficit produces a slower, steadier half-pound loss per week — this is often more sustainable and preserves more muscle mass. For weight loss, most experts recommend a deficit of no more than 500-750 calories below TDEE.

For lean muscle gain, a surplus of 250-500 caloriesabove TDEE is the standard recommendation. Larger surpluses don't build muscle faster — they just add more body fat. Beginners can get away with a slightly larger surplus (closer to 500) because their bodies are primed for rapid muscle growth, while experienced lifters benefit from keeping the surplus smaller (around 200-300 calories) to minimize fat gain.

Recalculate regularly. As your weight changes, your TDEE changes with it. A person who loses 20 pounds will have a meaningfully lower TDEE than before. Recalculating every 4-6 weeks — or whenever you hit a plateau — keeps your targets accurate.

Calories tell you how much to eat, but macronutrients determine what to eat. The three macronutrients — protein, carbohydrates, and fat — each play a distinct role in body composition and performance.

Protein is the most important macronutrient for body composition. It preserves muscle during a caloric deficit, builds muscle during a surplus, and has the highest thermic effect of food (your body burns 20-30% of protein calories just digesting it). A good target is 0.7-1.0 grams per pound of body weight per day. Each gram of protein provides 4 calories.

Fat is essential for hormone production, vitamin absorption, and brain function. Dropping fat too low can impair testosterone and estrogen levels. Aim for 20-35% of total calories from fat. Each gram of fat provides 9 calories.

Carbohydratesfill the remaining calories after protein and fat are set. They're your body's preferred fuel source for high-intensity exercise. Active people and athletes generally perform better with higher carb intakes, while sedentary individuals may do well with moderate carbs. Each gram of carbohydrate provides 4 calories.

A practical starting split for someone focused on body composition: set protein at 1 g/lb of body weight, set fat at 25% of total calories, and fill the rest with carbs. Adjust based on how you feel, perform, and progress.