Calculator

TDEE Calculator

Your total daily energy expenditure, reported as a range instead of a fake-precise number.

Most people overestimate this by one level. If you have a desk job and train 4 times a week, you are "Light" or "Moderate", not "Very".

If you have a DEXA, InBody, or caliper reading, entering it switches the calculation to Katch-McArdle, which is more accurate at the extremes of body composition. Leave blank to use Mifflin-St Jeor.

Adaptive TDEE: measure it instead of predicting it

Every equation above is a population average applied to one person. The only way to know your actual TDEE is to track intake and weight for two to four weeks and do the arithmetic backwards. Enter your real data below.

Use a weekly average of daily weigh-ins for both numbers, not two single-day readings. Day-to-day water shifts of 2 to 4 lb will otherwise swamp the signal.

How this works

Total daily energy expenditure is the sum of four components. Basal metabolic rate (BMR) is what you burn at complete rest and accounts for roughly 60 to 70 percent of the total. The thermic effect of food (TEF) is the energy cost of digesting and storing what you eat, around 10 percent of intake on a mixed diet. Exercise activity thermogenesis (EAT) is deliberate training. Non-exercise activity thermogenesis (NEAT) covers everything else: walking, fidgeting, standing, posture, gesturing.

NEAT is the component that makes a single-number TDEE estimate dishonest. Between two people matched for age, sex, height, weight, and training volume, NEAT can differ by 2,000 kcal per day. It also moves within a person: NEAT falls during a calorie deficit and rises during overfeeding, which is a large part of why weight loss slows even when the diet does not change.

The equations

Without a body fat measurement, this calculator uses Mifflin-St Jeor, which the Academy of Nutrition and Dietetics has recommended as the most reliable predictive BMR equation for non-obese and obese adults:

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

When you supply a body fat percentage, the calculator switches to Katch-McArdle, which is driven by lean body mass rather than total weight. That matters at the extremes: a 200 lb bodybuilder at 8 percent body fat and a 200 lb sedentary adult at 35 percent body fat have meaningfully different resting metabolic rates, and Mifflin-St Jeor gives them nearly the same number.

BMR = 370 + 21.6 x lean body mass(kg)

Why a range, not a number

Mifflin-St Jeor predicts measured BMR within 10 percent for roughly 70 to 80 percent of people. That means one person in four or five is already outside a 10 percent band before an activity multiplier is applied, and the activity multiplier carries its own error, which is larger than the equation's. Reporting "2,347 kcal/day" implies a precision that the underlying science does not support.

The range shown above is approximately plus or minus 8 percent around the point estimate. Treat it as a starting hypothesis, not a measurement. It exists to give you a defensible place to begin, after which the adaptive calculation replaces it with something real.

Use the estimate for two weeks, then throw it away. Eat at the midpoint of the range, weigh yourself daily under the same conditions, average by week, and feed those numbers into the adaptive calculator. Two to three weeks of your own data beats any equation.

Reading the adaptive result

The adaptive calculation uses the energy equivalent of body mass change, conventionally 3,500 kcal per pound (7,700 kcal per kg). This constant assumes the tissue gained or lost is mostly fat. Over short windows or during aggressive deficits, some of the change is glycogen and its associated water, which carries roughly 1,100 kcal per pound rather than 3,500, so short tracking windows overstate the correction. Ten days is the practical minimum; three to four weeks is better.

Not a weight loss prescription. Very low calorie intakes carry real risks including muscle loss, gallstones, micronutrient deficiency, and menstrual disruption. This tool caps its suggested deficits well above starvation ranges, but intake targets below roughly 1,200 kcal/day for women or 1,500 kcal/day for men should be medically supervised.

Related calculators

Macro Calculator splits this number into protein, carbohydrate, and fat.
Body Fat Estimator gives you the body fat percentage that unlocks Katch-McArdle.
Body Composition Tracker feeds real InBody or DEXA lean mass into this calculation and tracks it over time.
Protein Intake Calculator sets the protein floor for a deficit.

References

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.

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.

Pontzer H, Yamada Y, Sagayama H, et al. Daily energy expenditure through the human life course. Science. 2021;373(6556):808-812.

Martin A, Fox D, Murphy CA, et al. Tissue losses and metabolic adaptations both contribute to the reduction in resting metabolic rate following weight loss. Int J Obes. 2022;46(6):1168-1175.

Hall KD. What is the required energy deficit per unit weight loss? Int J Obes. 2008;32(3):573-576.