TDEE Calculator

A TDEE Calculator estimates your Total Daily Energy Expenditure - the number of calories your body burns in a day once you account for both your resting metabolism and your physical activity. Enter your sex, age, height, weight, and how active you are, and the tool returns your BMR, your TDEE, daily calorie targets for losing or gaining weight, and a suggested macronutrient split.

TDEE is the single most useful number for planning nutrition, because it is your maintenance calorie level: eat around it and your weight stays stable, eat below it and you lose weight, eat above it and you gain. The calculation starts from your Basal Metabolic Rate (BMR) - the energy you would burn at complete rest - computed with the Mifflin-St Jeor equation, which research has found to be the most accurate of the common predictive formulas for most people. That BMR is then multiplied by an activity factor from 1.2 for a sedentary lifestyle up to 1.9 for people who train hard twice a day or have physically demanding jobs.

Everything is calculated instantly in your browser. Your age, height and weight are never uploaded or stored, so your body metrics stay on your device. The result is an estimate, not a medical measurement: predictive equations carry an inherent margin of error, and factors like body composition, genetics, and medical conditions all shift real energy needs. Use it as a starting point, then adjust based on how your weight responds over two to three weeks.

The Mifflin-St Jeor equation is the most accurate of the common BMR formulas and still carries roughly a ten per cent error for any given person, because it estimates from height, weight, age and sex without knowing body composition. The activity multiplier adds more uncertainty than the equation does, since most people overestimate their activity level: if the number is not matching reality after a few weeks, that is usually the field to adjust. Treat the result as a starting point to test against actual weight change, not as a target.

A worked example shows why a TDEE calculator for women gives a lower figure than one for men with the same body. Take a 35-year-old who is 165 cm tall, weighs 65 kg and is moderately active (×1.55). Choosing Female gives a BMR of 1,345 and a TDEE of 2,085 kcal a day; choosing Male gives 1,511 and 2,342. The only difference is the sex constant, -161 against +5, a 166 kcal gap that the activity factor stretches to 257. For weight loss, the female figure becomes 1,585 kcal a day. So when you judge TDEE calculator accuracy, the inputs matter as much as the formula.