How to Calculate TDEE: Formula, Activity Levels and Limits

What TDEE means

Total daily energy expenditure (TDEE) is an estimate of how much energy your body uses across an average day. It combines resting energy with movement, training and the energy used to digest food. Because daily activity varies, TDEE is best treated as a starting range rather than a fixed personal constant.

Step 1: estimate resting energy

CalcQuick uses the Mifflin–St Jeor equation. It combines weight in kilograms, height in centimeters and age, with a sex-specific constant. The answer is basal metabolic rate (BMR): an estimate of energy use at rest.

Step 2: choose an activity multiplier

Multiply BMR by an activity factor. A sedentary estimate often uses 1.2; light activity 1.375; moderate activity 1.55; and very active routines 1.725. Choose based on the pattern of a normal week, not the hardest day.

• Sedentary: little structured exercise
• Light: about 1–3 active sessions each week
• Moderate: about 3–5 active sessions
• Very active: hard training most days

Worked example: follow the formula

Consider a 30-year-old woman who weighs 65 kg and is 165 cm tall. The equation gives 10 × 65 + 6.25 × 165 − 5 × 30 − 161 = 1,370.25 kcal per day at rest. With a moderate activity multiplier of 1.55, the estimated total is 1,370.25 × 1.55 = 2,123.8875, displayed as about 2,124 kcal per day.

This is an illustration of the calculation, not a personal food-intake prescription. In the calorie calculator, choose metric units and enter these values to reproduce the example. With US customary units, the calculator converts pounds, feet and inches before applying the same equation. Keep intermediate values unrounded when checking the answer.

How much does the activity choice matter?

Using the same resting estimate, a light factor of 1.375 gives about 1,884 kcal, while 1.55 gives about 2,124 kcal. That difference of roughly 240 kcal comes entirely from the activity assumption. Changing a dropdown does not measure a change in your metabolism.

Exercise frequency alone does not capture everything you do during a day. Consider your usual work, travel and movement as well as training. If two descriptions seem equally plausible, compare both outputs as scenarios instead of treating the extra digits in one result as certainty.

Common calculation mistakes

Check the unit selection before entering a height or weight: 165 centimeters is not 165 inches. Use your current values and a representative activity setting. The activity multiplier already models activity, so adding a separate full estimate of exercise calories to this result can count the same activity twice.

A TDEE estimate describes total energy expenditure. A macro calculator answers a different question: how a chosen calorie amount divides into grams of protein, carbohydrate and fat. If you continue to that tool, enter the calorie amount you intend to model; it does not independently verify that the amount is appropriate for you.

Use the estimate as a baseline

Compare the estimate with several weeks of body-weight and energy trends. Sleep, illness, medication, pregnancy and individual metabolism can change needs. A clinician or registered dietitian can help when the number affects a medical or nutrition plan.