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Maintenance, cut, or bulk — get your daily number.
Every diet plan reduces to energy balance: eat at your maintenance level and weight stays flat, below it and you lose, above it and you gain. This calculator estimates your maintenance calories (TDEE) with the Mifflin-St Jeor equation — the formula the Academy of Nutrition and Dietetics rates most accurate for most adults — then gives practical targets for fat loss and muscle gain.
The starting point of every diet that works: you cannot manage what you have not measured. People use this to get their maintenance number before a cut or bulk, then come back to adjust it as weight changes. It turns "eat less" into a specific, testable daily target.
Within roughly ±10% for most people — good enough to start. Track your weight for 2–3 weeks at the computed intake; if you are not trending as expected, adjust by 100–200 kcal.
A 500 kcal daily deficit targets about 0.5 kg (1 lb) per week — fast enough to see progress, slow enough to preserve muscle and sanity. Larger deficits mostly trade muscle for speed.
Most people overestimate. Desk job with 3 gym sessions a week is usually 1.4–1.5, not 1.7. When in doubt, pick the lower option and adjust from real results.