What this tool does
This calculator first estimates basal metabolic rate (BMR) with the Mifflin-St Jeor equation, then applies a standard activity multiplier to estimate total daily energy expenditure (TDEE). The result is best treated as a starting estimate that can be calibrated against real weight and intake trends over time.
How to use it
- Enter your current age, height and weight.
- Choose the sex constant used by the Mifflin-St Jeor equation.
- Choose the activity level that best represents a normal week.
- Use the TDEE estimate as a maintenance starting point, then compare it with real-world progress.
Important limitations
These numbers are planning estimates, not a diagnosis or individualized medical advice. They can be less appropriate during pregnancy, breastfeeding, adolescence, illness, recovery from an eating disorder, or when a clinician has given you specific nutrition instructions.
Frequently asked questions
Is TDEE the same as BMR?
No. BMR estimates energy used at rest. TDEE adds an activity multiplier to estimate total daily energy needs.
Why can my real maintenance calories differ?
Activity multipliers are broad categories and individuals differ. Tracking body weight and intake over several weeks gives better personal calibration.
Does this calculator store my data?
Basic profile fields can be stored in your browser so other GentleTools Fitness calculators can reuse them. Nothing is replaced with demo data.