Which TDEE formula is most accurate?

There is no single most accurate formula for everyone. Mifflin-St Jeor is a practical default when body fat is unknown. Katch-McArdle can be useful when body fat percentage is reliable because it uses lean body mass.

Why do different TDEE calculators give different results?

Different calculators may use different BMR equations, activity multipliers, rounding rules, body fat inputs or calorie deficit assumptions.

Should I average all TDEE formulas?

Averaging formulas can be a useful reference, but it is usually better to choose a formula that fits your available inputs and then calibrate with real weight trend data.

Interactive formula visualizer

TDEE Formulas Compared: Which One Fits Your Body?

Enter your stats once and compare major calorie formulas side by side. This helps explain why different TDEE calculators can give different maintenance-calorie estimates.

Compare your formulas

Unit system

Imperial Metric

Gender

Male Female

Age

Activity level

Not sure? Take the Activity-Level Quiz.

Weight

Height

Body fat % (optional)

Katch-McArdle requires a reasonable body-fat estimate because it uses lean body mass.

Use main TDEE calculator

Your comparison will appear here

Enter your stats to see Mifflin-St Jeor, Harris-Benedict and Katch-McArdle estimates side by side.

Tip: If body fat percentage is unknown, compare Mifflin-St Jeor and Harris-Benedict first. Add Katch-McArdle only when your body-fat estimate is realistic.

Why TDEE calculators disagree

Most TDEE calculators start by estimating BMR, then multiply it by activity level. If two calculators use different BMR equations or different activity assumptions, the final TDEE can differ by hundreds of calories.

Mifflin-St Jeor

A practical default formula based on sex, age, height and weight. It is often a good starting point when body fat percentage is unknown.

Revised Harris-Benedict

Another common BMR equation using sex, age, height and weight. For some users it can produce higher estimates than Mifflin-St Jeor.

Katch-McArdle

A lean-mass-based formula. It can be useful for athletic or body-composition-aware users, but it depends on a reliable body-fat estimate.

Next step: Use the TDEE Calibration Tool after 2–4 weeks of tracking, or use the Activity-Level Quiz if your biggest uncertainty is activity, or read the Katch-McArdle guide if your biggest uncertainty is body fat percentage.

TDEE Formula FAQ

Which formula should I trust?

Use Mifflin-St Jeor as a practical default when body fat percentage is unknown. Use Katch-McArdle when body fat percentage is reasonably estimated. Then adjust using real weight trend data.

Is Katch-McArdle always better?

No. It can be better for some people because it uses lean mass, but only when the body-fat estimate is realistic. A bad body-fat estimate can produce a bad calorie estimate.

Why is the formula range useful?

The range shows how much uncertainty exists before real-world tracking. If formulas differ by 300 calories, your best next step is to start conservatively and recalibrate with progress data.

Calculate your full result

After comparing formulas, use the main calculator to estimate maintenance, cutting and bulking calories plus macros.

Open the TDEE Calculator Calibrate after tracking