TDEE — How Many Calories Do You Need?

Your Total Daily Energy Expenditure (TDEE) is the total calories your body burns daily. The TDEE calculator estimates this using the Mifflin-St Jeor equation based on your age, gender, weight, height, and activity level.

To lose weight: eat below your TDEE (a 500 calorie daily deficit ≈ 1 lb/week loss). To gain: eat above. To maintain: eat at your TDEE. These are the fundamentals — everything else is detail.

BMI — Useful but Limited

The BMI calculator divides weight by height squared and categorizes the result: under 18.5 (underweight), 18.5-24.9 (normal), 25-29.9 (overweight), 30+ (obese). BMI is a useful population screening tool but does not distinguish muscle from fat — it can misclassify athletes and elderly individuals.

Body Fat Percentage — A Better Measure

The body fat calculator uses the U.S. Navy method (neck, waist, hip measurements) for a more informative assessment. Healthy ranges: men 10-20%, women 18-28%. Body fat percentage directly measures what BMI only estimates.

Water Intake — Stay Hydrated

The water intake calculator estimates daily needs based on your weight, activity, and climate. A starting guideline: half your body weight in ounces (160 lbs = 80 oz). Adjust upward for exercise, hot weather, and altitude. Track intake for two weeks to build the habit.

Putting It All Together

• Calculate your TDEE first — it is the foundation of any nutrition plan
• Use body fat percentage as your primary metric, not BMI alone
• Recalculate as your weight changes — TDEE shifts with body composition
• These tools provide estimates — consult a healthcare professional for medical decisions