How to use this calculator
Choose US or metric units, then enter your sex, age, height, weight and activity level. Under Formula & body fat you can switch the BMR equation and, if you know it, add your body fat percentage. You’ll get:
- your TDEE, the calories you burn on a typical day
- how it splits between basal metabolic rate and activity and digestion
- your BMR from all three formulas, side by side
- a table of your TDEE at every activity level, per day and per week
Once you know your TDEE, the calorie calculator turns it into a target for losing or gaining weight, and the macro calculator splits that target into protein, carbs and fat.
The formula
TDEE is your basal metabolic rate multiplied by an activity factor:
The calculator offers three ways to estimate BMR. All use weight in kilograms, height in centimeters and age in years.
Mifflin-St Jeor (1990), the default:
Harris-Benedict, revised by Roza and Shizgal (1984):
Katch-McArdle, which needs your body fat percentage to work out lean body mass (LBM):
The activity factors are the conventional multipliers used by most TDEE calculators: 1.2, 1.375, 1.55, 1.725 and 1.9. They aren’t measured values. They’re broad categories that cover your exercise, daily movement and the energy used to digest food.
Worked example
A 35-year-old woman who is 5 ft 5 in (165.1 cm), 160 lb (72.6 kg) and lightly active:
- Mifflin-St Jeor BMR: 10 × 72.6 + 6.25 × 165.1 − 5 × 35 − 161 = 1,422 calories
- TDEE: 1,422 × 1.375 = 1,955 calories a day
Her BMR accounts for 73% of that total and activity and digestion for the other 27%. The revised Harris-Benedict equation gives her a BMR of 1,479, about 4% higher. Across the five activity levels her TDEE ranges from 1,706 (sedentary) to 2,701 (extra active), a spread of nearly 1,000 calories. That’s why choosing the right activity level matters more than choosing the formula.
TDEE at every activity level
The table shows TDEE from the Mifflin-St Jeor equation for two example 35-year-olds: a woman who is 5 ft 4 in and 150 lb (BMR 1,360) and a man who is 5 ft 10 in and 190 lb (BMR 1,803).
| Activity level | Multiplier | Woman, 150 lb | Man, 190 lb |
|---|---|---|---|
| Sedentary: little or no exercise | 1.2 | 1,632 | 2,164 |
| Light: exercise 1–3 days a week | 1.375 | 1,871 | 2,479 |
| Moderate: exercise 3–5 days a week | 1.55 | 2,109 | 2,795 |
| Very active: hard exercise 6–7 days a week | 1.725 | 2,347 | 3,110 |
| Extra active: physical job or twice-daily training | 1.9 | 2,585 | 3,426 |
Choosing your activity level
Most people overestimate how active they are. A few guidelines help:
- Sedentary fits a desk job with little walking and no regular workouts.
- Light fits a desk job plus a few workouts or long walks a week.
- Moderate fits most days with 30 to 60 minutes of purposeful exercise, or a job that keeps you on your feet.
- Very active and extra active are for hard daily training, manual labor, or both.
If you’re between two levels, take the lower one. Track your weight for two to three weeks while eating at that TDEE. If your weight is steady, you’ve found your number. If it drifts, adjust by 100 to 200 calories.
When to use Katch-McArdle
Equations based on height and weight assume an average body composition. Someone with a lot of muscle will burn more than predicted, and someone with a higher body fat percentage may burn less. Katch-McArdle sidesteps this by working only from lean mass, so it can be the better choice when you have a reliable body fat measurement, such as from a DEXA scan. Estimates from bathroom scales can be off by several percentage points, which can make Katch-McArdle less accurate, not more. To compare all three formulas in detail, use the BMR calculator.
Assumptions and limitations
- All three equations were developed from adults and estimate averages. In a 2005 systematic review, even the best equation (Mifflin-St Jeor) missed measured resting metabolism by more than 10% for some people.
- The activity multipliers are rough categories. Two people with the same label can burn very different amounts.
- TDEE changes as your weight, muscle mass and routine change, so recalculate after any big shift.
- The results don’t apply during pregnancy or breastfeeding, or to children and teens.
Sources
- Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247.
- Roza AM, Shizgal HM. The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass. Am J Clin Nutr. 1984;40(1):168–182.
- McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance. Wolters Kluwer (source of the Katch-McArdle equation).
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789.
These are estimates for healthy adults and aren’t medical advice. If you have a medical condition that affects your metabolism, ask your doctor or a registered dietitian.
Frequently asked questions
What is TDEE?
Total daily energy expenditure is the number of calories you burn in a full day. It combines your basal metabolic rate (the energy to keep your body running at rest), the energy used to digest food, and everything you do while moving, from workouts to walking around the house. Eating at your TDEE keeps your weight roughly stable.
How is TDEE calculated?
The calculator estimates your BMR with a published equation, then multiplies it by an activity factor between 1.2 (sedentary) and 1.9 (extra active). For a lightly active 35-year-old woman who is 5 ft 5 in and 160 lb, that's 1,422 × 1.375 ≈ 1,955 calories a day.
Which formula should I use?
Mifflin-St Jeor is the default because a 2005 systematic review found it predicted resting metabolism within 10% of measured values more often than other equations. If you know your body fat percentage fairly accurately, Katch-McArdle can suit lean or very muscular people better because it works from lean mass.
Is TDEE the same as maintenance calories?
Yes. Your TDEE is the intake that should keep your weight steady. To lose about a pound a week, eat roughly 500 calories less than your TDEE; to gain, eat a little more.
Why is my TDEE different on other calculators?
Calculators use different BMR equations and activity multipliers, and small changes in the multiplier move the answer more than anything else. A difference of 100 to 200 calories is normal. Your weight trend over a few weeks is the best way to find your true number.
Do I need my body fat percentage?
No. It's optional and only adds the Katch-McArdle formula. If your body fat estimate comes from a bathroom scale, it may be less reliable than the formulas that use height and weight.
Updated November 2026. Results are estimates for educational purposes and depend on the inputs you provide.