Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day, including everything from breathing and digestion to workouts and walking. It's the single most useful number for planning fat loss, muscle gain, or maintenance, because it tells you roughly how many calories you eat to stay the same weight.
Knowing your TDEE turns guesswork into a plan. Eat below it and you lose weight; eat above it and you gain. This free calculator works in metric and US units and updates live as you change your inputs.
How the tdee calculator works
This calculator uses a two-step method. First it estimates your Basal Metabolic Rate (BMR) with the Mifflin-St Jeor equation, the most accurate standard formula for most people:
- Men: BMR = 10 x weight(kg) + 6.25 x height(cm) − 5 x age + 5
- Women: BMR = 10 x weight(kg) + 6.25 x height(cm) − 5 x age − 161
Then it multiplies your BMR by an activity factor to get TDEE:
TDEE = BMR x activity factor
The activity factors are: Sedentary 1.2 (little or no exercise), Light 1.375 (1–3 days/week), Moderate 1.55 (3–5 days/week), Very active 1.725 (6–7 days/week), and Athlete 1.9 (hard daily training or a physical job).
You need four inputs: sex, weight, height, and age, plus your activity level. The tool then shows three targets: Lose (TDEE − 500), Maintain (TDEE), and Gain (TDEE + 500). A 500 kcal/day difference equals roughly 0.45 kg (1 lb) of body weight per week.
Worked example
Take a 30-year-old man who weighs 80 kg and is 180 cm tall, training 3–5 days a week (Moderate, factor 1.55).
First, his BMR: (10 x 80) + (6.25 x 180) − (5 x 30) + 5 = 800 + 1125 − 150 + 5 = 1780 kcal/day.
Then his TDEE: 1780 x 1.55 = 2759 kcal/day (maintenance).
To lose about 0.45 kg (1 lb) per week he'd eat 2759 − 500 = 2259 kcal/day; to gain, 2759 + 500 = 3259 kcal/day.
Things to keep in mind
- TDEE is an estimate, not a measurement. Real-world energy needs vary by genetics, muscle mass, hormones, and non-exercise movement (NEAT), so treat the number as a starting point and adjust based on how your weight actually trends over 2–4 weeks.
- Activity factors are broad buckets. Two people who both train 4 days a week can have very different total expenditure, so it's easy to over- or under-estimate by picking the wrong multiplier.
- The 500 kcal = 1 lb/week rule is a simplification. Weight loss often slows as your body adapts and your TDEE drops with body weight, so deficits may need recalculating over time.
- This tool is for general fitness planning, not medical or clinical nutrition advice. If you're pregnant, have a medical condition, or are very lean or very heavy, consult a doctor or registered dietitian.
Frequently asked questions
What is TDEE and why does it matter?
TDEE (Total Daily Energy Expenditure) is the total calories you burn in a day, including your resting metabolism, digestion, daily movement, and exercise. It matters because it equals your maintenance calories: eat below it to lose weight, above it to gain, and at it to stay the same.
How is TDEE calculated?
TDEE is calculated by finding your BMR with the Mifflin-St Jeor equation, then multiplying it by an activity factor between 1.2 (sedentary) and 1.9 (athlete). The formula is TDEE = BMR x activity factor, where the factor reflects how active you are each day.
What activity level should I choose?
Pick Sedentary (1.2) for little or no exercise, Light (1.375) for 1–3 days/week, Moderate (1.55) for 3–5 days/week, Very active (1.725) for 6–7 days/week, and Athlete (1.9) for hard daily training or a physically demanding job. When unsure, choose the lower option.
How many calories should I eat to lose weight?
To lose about 0.45 kg (1 lb) per week, eat 500 calories below your TDEE each day. This calculator shows that Lose target automatically. Avoid very aggressive deficits; a 500 kcal/day cut is sustainable for most people and protects muscle and energy.
Is the Mifflin-St Jeor equation accurate?
Mifflin-St Jeor is widely regarded as the most accurate BMR formula for the general population and is preferred by many dietitians. It's still an estimate, though, so use your real weight trend over a few weeks to fine-tune your calorie target.
How often should I recalculate my TDEE?
Recalculate whenever your weight changes by a few kilograms or your activity level shifts, since both change how many calories you burn. As you lose or gain weight, your BMR and TDEE move too, so updating every 4–6 weeks keeps your targets realistic.