BMR & TDEE Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation, plus calorie targets for weight loss and gain based on your activity level.
Input
How much you exercise in a typical week
Output
| Metric | Value |
|---|---|
| No data yet | |
Guides
What is BMR and TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep you alive — breathing, circulating blood, repairing cells, and running your organs. It's the energy floor: the minimum you'd burn lying in bed all day.
TDEE (Total Daily Energy Expenditure) builds on top of that. It's your BMR multiplied by an activity factor that accounts for exercise, daily movement, and the extra energy your body spends digesting food. TDEE is the number that actually matters for weight management — eat below it and you lose weight, eat above it and you gain weight, eat at it and your weight holds steady.
The formula used
This calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate BMR formula for the general population (more accurate than the older Harris-Benedict equation, which tends to overestimate calorie needs):
- Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) + 5
- Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) − 161
TDEE is then BMR multiplied by an activity multiplier:
| Activity level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise |
| Lightly active | 1.375 | Light exercise 1-3 days/week |
| Moderately active | 1.55 | Moderate exercise 3-5 days/week |
| Very active | 1.725 | Hard exercise 6-7 days/week |
| Extra active | 1.9 | Very hard exercise or a physical job |
How to use it
- Enter your weight and pick kg or lb.
- Enter your height and pick cm or in.
- Enter your age and select your sex (the Mifflin-St Jeor equation uses a different constant for each).
- Pick the activity level that best matches your typical week.
- The table updates instantly with your BMR, TDEE, and calorie targets 500 calories below and above maintenance — a common starting point for weight loss or weight gain goals.
FAQ
Why do I need to enter my sex? Men typically carry more lean muscle mass than women at the same weight and height, which burns more calories at rest. The formula adjusts for this with a different constant.
Why 500 calories above/below TDEE? A deficit or surplus of roughly 500 calories per day corresponds to about one pound (0.45 kg) of body weight change per week, since one pound of body fat holds roughly 3,500 calories. It's a simple starting point, not a precise guarantee — real-world change also depends on metabolic adaptation and water retention.
Is Mifflin-St Jeor always accurate? No formula is perfect for every individual — it's a population-level estimate, closer to measured BMR than the older Harris-Benedict equation for most adults. Unusually high muscle mass and certain medical conditions can shift your real number.
Does this calculator store my data? No. Everything runs in your browser — your inputs and results are never sent to or stored on our servers.
Is this medical advice? No. This tool gives a general estimate for informational purposes only. For personalized nutrition or weight-management guidance, consult a doctor or registered dietitian.