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TDEE / Calorie Needs Calculator

Estimate resting energy expenditure with the Mifflin-St Jeor equation and multiply by an editable activity factor for TDEE.

Estimate TDEE and resting energy expenditure

Use the Mifflin-St Jeor equation for resting energy expenditure (REE), then apply an activity factor to estimate total daily energy expenditure.

Estimated REE—
Estimated TDEE—
Activity factor used—

TDEE calculator formula

The first step is Mifflin-St Jeor resting energy expenditure: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, plus 5 for the male equation or minus 161 for the female equation. The original study derived the equation from measured resting energy expenditure in healthy adults. Mifflin et al. study.

From REE to TDEE

Total daily energy expenditure is estimated by multiplying REE by an activity factor. The factor is the least precise part of a simple TDEE calculator because real daily movement, occupation and training load vary continuously.

Why TDEE is not a fixed personal number

Energy expenditure changes with activity, body composition, temperature, illness, training and other factors. Treat the result as a starting estimate rather than a measurement.

Health and nutrition limitation

This tool does not prescribe a calorie deficit, weight-loss target or medical nutrition plan. People with medical, pregnancy, eating-disorder or performance-nutrition needs should use individualized professional guidance.

Treat TDEE as a starting estimate, then calibrate

Activity multipliers compress many behaviors into one category, so estimated TDEE can differ meaningfully from real energy expenditure. If body weight is stable over several weeks under consistent intake tracking, that observed intake can help calibrate the estimate. Changes in training volume, occupation, sleep, illness and body mass can change expenditure. For medical nutrition, eating disorders, pregnancy or other health conditions, use individualized professional guidance rather than a generic calculator.

Frequently asked questions

What equation does the TDEE calculator use?
It uses the Mifflin-St Jeor resting energy expenditure equation and multiplies the result by the activity factor you select.
Is REE the same as TDEE?
No. REE estimates energy used at rest, while TDEE attempts to include daily activity by multiplying REE by an activity factor.
How accurate are activity factors?
They are broad planning assumptions. Two people in the same activity category can have meaningfully different actual energy expenditure.
Does this calculator tell me how many calories to eat for weight loss?
No. It estimates energy expenditure only and does not prescribe a calorie target or medical nutrition plan.