Science-backed calculator
Calorie Needs Calculator
Estimate daily calories for fat loss, maintenance, or lean mass gain using body size, activity, NEAT, and training frequency. This tool uses the Mifflin-St Jeor equation as a practical starting point, then layers in real-world activity adjustments.
Used as a practical proxy for baseline NEAT.
This calculator provides an evidence-informed starting estimate. Actual energy needs vary with body composition, metabolic adaptation,
medications, illness, sleep, hormone status, and training quality. Translation: your metabolism did not read the spreadsheet.
How this works
- BMR is estimated using the Mifflin-St Jeor equation.
- Baseline daily burn is adjusted using lifestyle activity, daily steps, and weekly training volume.
- Goal calories are then set for weight loss, maintenance, or mass gain using practical surpluses and deficits.
- Macro and support targets include protein, fat, carbs, fibre, hydration, sodium guidance, and suggested protein distribution across meals.
Important note
- This is not a diagnosis or individualized medical nutrition prescription.
- People with eating disorders, pregnancy, significant endocrine disease, or complex medical issues should use clinician-guided planning.
- For many people, maintenance is more boring than fat loss or bulking. It is also wildly underrated.
- Hydration and sodium needs vary with sweat rate, climate, medications, blood pressure, kidney disease, and medical history.