Daily Calorie Calculator

Your daily calorie needs depend on your age, sex, height, weight, and activity level. A common method is to estimate your BMR with the Mifflin-St Jeor equation and multiply it by an activity factor (1.2–1.9) to get your Total Daily Energy Expenditure (TDEE). Eating at your TDEE maintains weight; a deficit loses weight; a surplus gains it. Our free calculator does all of this instantly.

A deficit of roughly 500 kcal per day below your TDEE typically produces about 0.5 kg (1 lb) of fat loss per week — the evidence-based sweet spot. A milder 250 kcal deficit gives a more sustainable ~0.25 kg/week, while 750 kcal accelerates to ~0.75 kg/week but is harder to maintain. Clinical guidance recommends not eating below your BMR (or about 1,200 kcal/day) without medical supervision.

To build lean mass, eat a surplus of roughly 250–500 kcal above your TDEE. A 250 kcal surplus supports a slow, lean gain (~0.25 kg/week) with minimal fat accumulation, while 500 kcal accelerates growth (~0.5 kg/week) but adds some fat. Pair the surplus with progressive resistance training and adequate protein (1.6–2.2 g per kg of body weight) to maximize muscle synthesis.

BMR (Basal Metabolic Rate) is the energy your body burns at complete rest to keep your heart beating and cells working — roughly 60–70% of your daily burn. TDEE (Total Daily Energy Expenditure) adds everything else: exercise, walking, and daily movement. You can think of BMR as the floor and TDEE as your true daily calorie budget — eat at your TDEE to maintain, below it to lose, and above it to gain.

A common evidence-based split sets protein from body weight (1.6–2.2 g per kg, higher when cutting to preserve muscle), fat at about 25% of total calories, and carbohydrates filling the remaining calories. Protein and carbs provide 4 kcal per gram, while fat provides 9 kcal per gram. Our calculator applies this automatically to your chosen calorie target.

As you lose weight, your BMR falls because a smaller body burns fewer calories at rest, so your TDEE — and therefore your maintenance calories — drops. This is why calorie targets are not static. As a rule of thumb, re-calculate your calorie needs whenever your weight changes by more than about 2 kg or your activity level shifts.

Clinical guidance generally recommends not eating below your BMR, or roughly 1,200 kcal per day for most adults, without medical supervision. Eating below this level for long periods can slow metabolism, cause muscle loss, and create nutrient deficiencies. Our calculator automatically flags targets that fall below this safety floor.

Yes. The calculator is 100% free with no registration, and every calculation runs entirely in your browser — no data is ever sent to a server. If you choose to save results, they are stored only in your browser's localStorage, and you can export, import, or clear your history at any time.