Enter your sex, age, height, weight, and an honest activity level above, and you get your estimated TDEE — total daily energy expenditure — the calories your body burns in a typical day, alongside your BMR and example cut and bulk targets. This TDEE calculator uses the Mifflin-St Jeor equation, the formula with the strongest accuracy record in validation studies, and it runs entirely in your browser with the math and sources shown below.
How to use
- Choose units — the metric/imperial toggle converts your entries either way.
- Enter sex, age, weight, and height — the four inputs the equation needs.
- Pick the activity level that matches your real week, not your aspirational one.
The maintenance number updates as you type; the smaller figures show a −500 kcal/day cut estimate and a +300 kcal/day bulk estimate derived from it. The URL updates too, so you can bookmark or share a scenario.
What TDEE is actually made of
Your daily burn has four parts. The largest is basal metabolic rate — the energy that keeps organs running at complete rest — typically 60–70% of the total. Digestion (the thermic effect of food) adds roughly another 10%. The rest is movement, split between deliberate exercise and NEAT — non-exercise activity like walking to the shop, taking stairs, and fidgeting — which varies enormously between people and explains why two colleagues with identical stats can maintain weight on very different intakes. A calculator estimates the BMR part with an equation and wraps everything else into one activity multiplier, which is why the multiplier you choose matters more than any other input.
Picking an activity level honestly
This is where most estimates go wrong. The multipliers describe your whole week, not your best day. A desk job with no workouts is sedentary (×1.2). A desk job plus one to three gym sessions is lightly active (×1.375). Training three to five days a week puts most office workers at moderately active (×1.55) at most. Very active (×1.725) fits daily hard training or physically demanding work — servers, tradespeople, and nurses on their feet all shift. Extra active (×1.9) means a physical job plus serious training, such as construction work plus evening sport. When in doubt, choose the lower level, compare the number against two to four weeks of real weight data, and adjust.
Why every TDEE calculator gives a different number
Three reasons. First, the equation: this page uses Mifflin-St Jeor, which a systematic comparison published by the American Dietetic Association found the most reliable of the common formulas; other sites use the older Harris-Benedict (tends to run slightly high) or Katch-McArdle (requires body-fat percentage). Second, the multipliers: sites disagree on exact factors and labels. Third, rounding: we compute BMR unrounded and round exactly once at the final TDEE, so a saved link always reproduces the same number. In practice these differences sit well within the equations’ own error bars.
Energy needs and weight category are two views of the same question — our BMI calculator pairs naturally with this page and shows its formula the same way.
Limits
Mifflin-St Jeor was derived from measurements of healthy adults, and even there it lands within about 10% of measured resting metabolism for most people — a 2,500 kcal estimate is really a range of roughly 2,250–2,750 before the activity multiplier adds its own uncertainty. Actual measurement — indirect calorimetry for resting rate, doubly labeled water for total expenditure — is the only way to know your true number. Metabolism also adapts as weight changes, so re-run the estimate as your stats move. These figures are educational estimates, not nutrition or medical advice; for a personalized plan, particularly with any medical condition or a history of disordered eating, work with a clinician or registered dietitian.
Explore the rest of our calculators — every one shows its formula and sources — and our browser-based tools for files and text, which never upload your data either.