Free Calorie Calculator — BMR, TDEE & Macro Targets
Weight change obeys energy balance: eat below maintenance and you lose, above and you gain. This free calculator estimates your BMR (calories burned at rest) with the Mifflin-St Jeor equation — the most validated formula in nutrition science — multiplies by activity level for TDEE, then sets a daily target with protein/carb/fat gram splits for loss, maintenance, or muscle gain.
How to Get Your Numbers
- Enter stats honestly — age, height, weight in metric or imperial; pick the activity level matching a typical week, not your best one.
- Choose a goal — a 500 kcal deficit loses roughly a pound weekly; a 300 kcal surplus with training builds lean muscle.
- Eat to the macros — hit protein first (it preserves muscle while dieting), fill the rest with carbs and fats you enjoy enough to sustain.
BMR vs TDEE: Know Both
BMR is the cost of keeping you alive — breathing, circulation, brain function — roughly 60–70% of daily burn. TDEE adds movement and exercise on top. Dieting from BMR instead of TDEE is the classic crash-diet error: a 500 kcal deficit from a 2,400 TDEE is sustainable, while eating at a 1,500 BMR with training invites burnout, stalls, and binges. Recalculate every 5–10 lb lost, since lighter bodies burn less.
How accurate are calorie calculators?
Within roughly ±10–15% for most people — formulas predict averages, not individuals. Treat the target as a starting hypothesis, track weight for 2–3 weeks, then adjust by 100–200 kcal based on the trend.
How much protein do I need?
Evidence supports 1.6–2.2 g per kg of body weight when training, higher end while cutting. This tool targets ~30% of calories from protein, which lands most users in that band automatically.
Is this medical advice?
No — these are estimates for healthy adults, not prescriptions. Pregnancy, medical conditions, eating-disorder history, and medications all change the picture; consult a professional for personalized guidance.
Related Tools
Check your category with the BMI Calculator, convert units with the Unit Converter, and plan meal timing across zones with the Time Zone Converter.