❤️ Health & Fitness — Free Online Calculators & Tools

Standard BMI uses global WHO thresholds (overweight ≥25). However, South Asians (including Indians) have higher metabolic risk at lower BMI. Indian guidelines recommend: underweight <18.5, normal 18.5–22.9, overweight 23–24.9, obese ≥25. Our BMI calculator shows both WHO and India-specific classifications.

Calorie calculators estimate TDEE (Total Daily Energy Expenditure) using formulas like Mifflin-St Jeor. These are estimates with ±10–15% individual variation depending on genetics, muscle mass, and metabolism. Use as a starting point and adjust based on actual weight changes over 2–4 weeks.

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — keeping organs functioning. TDEE (Total Daily Energy Expenditure) = BMR × activity multiplier. TDEE is your actual daily calorie needs including movement. Most people have TDEE 20–70% higher than their BMR.

Multiple formulas exist: Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964). All are based on height above 5 feet. They were developed for clinical use and are approximations — the "ideal" weight range is more meaningful than a single number. Muscle mass, frame size, and body composition matter more than the number on a scale.

The Naegele's Rule (LMP + 280 days) used here is the standard medical method and is accurate on average. However, only ~5% of babies are born exactly on the due date — most births occur within 2 weeks before or after. Ultrasound dating in the first trimester is the most accurate method and may adjust the estimated due date.