Calorie Calculator

Calorie Calculator - Daily Calorie Needs (BMR & TDEE) | Tuttilo

Calculate your daily calorie needs with our accurate calorie calculator. Uses the Mifflin-St Jeor equation for precise BMR and TDEE calculations.

Enter your age, biological sex, current weight, and height using your preferred unit system. Select your activity level from sedentary to very active based on how much exercise you do weekly. Tuttilo uses the scientifically-validated Mifflin-St Jeor equation to calculate your Basal Metabolic Rate (BMR)—the calories you burn at rest—then multiplies by your activity factor to determine your Total Daily Energy Expenditure (TDEE). The results show your maintenance calories, plus targets for weight loss or weight gain. Your health data stays completely private in your browser.

Fitness enthusiasts starting new diet plans use TDEE calculations as the foundation for creating caloric deficits or surpluses. Personal trainers establish baseline calorie targets for clients before designing nutrition programs. People recovering from eating disorders work with therapists to understand healthy calorie ranges for their body and activity level. Athletes in weight-class sports calculate their maintenance calories to plan cuts or bulks before competitions. Individuals experiencing unexplained weight changes verify whether their calorie intake aligns with their expenditure.

BMR decreases as you lose weight, so recalculate every 10-15 pounds to avoid plateaus from eating too many calories for your new body size. Activity multipliers are rough estimates—track your actual weight changes over 2-3 weeks and adjust calories by 200-300 if results don't match expectations. Muscle burns more calories at rest than fat, so strength training increases your BMR over time even without cardio. Don't go below your BMR for extended periods, as severe deficits trigger metabolic adaptation where your body aggressively conserves energy, making further fat loss extremely difficult.

All processing happens directly in your browser. Your files never leave your device — no server uploads, no cloud storage, no data retention. The tool works offline once loaded, requires no registration, and is completely free with no usage limits.