Health & Fitness Calculators

The WHO classifies BMI as: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), and Obese (30 and above). BMI is a population-level screening tool only — it does not account for muscle mass, bone density, age, sex or ethnic differences. Asian populations may face metabolic risks at a lower BMI threshold of 23. Always consult a healthcare provider for a personalised assessment.

Daily calorie needs depend on age, sex, height, weight, and physical activity level. A sedentary adult male typically needs 2,000–2,500 kcal/day; a sedentary female roughly 1,600–2,000 kcal/day. Use our Calorie Calculator (based on the Mifflin–St Jeor equation) to get a personalised estimate and adjust for your activity multiplier.

BMR (Basal Metabolic Rate) is the energy your body burns at complete rest — just to maintain vital functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor that accounts for how active you are throughout the day. For weight management, TDEE is the more actionable number: eat below it to lose weight, above it to gain.

EFSA recommends a total water intake of 2.0 litres/day for women and 2.5 litres/day for men from all food and fluid sources. In Bangladesh's hot and humid climate — particularly from March to June — active adults should target 3.0–4.0 litres to compensate for sweat loss. Physical activity, body weight, and health conditions all influence this figure.

The National Sleep Foundation recommends 7–9 hours of sleep per night for adults aged 18–64, and 7–8 hours for those aged 65 and over. Our Sleep Calculator helps you identify the optimal bedtime aligned to 90-minute sleep cycles, so you wake up at the end of a cycle rather than in the middle of deep sleep — which reduces grogginess.

These calculators use validated, peer-reviewed formulas from organisations including the WHO, NIH, EFSA, and the American College of Sports Medicine (ACSM). They provide population-level estimates with typical accuracy within 10–20% for individuals. Individual results vary based on genetics, health conditions, and measurement precision. They are educational tools, not replacements for clinical assessment.

Body fat percentage is the proportion of total body mass that is fat tissue. Essential fat is 2–5% for men and 10–13% for women; athletic ranges are 6–13% for men and 14–20% for women. Our Body Fat Calculator uses the US Navy method (neck, waist, and hip measurements) or a BMI-derived method — both reasonable estimates when DEXA scans are not available.

eGFR (estimated Glomerular Filtration Rate) measures how well your kidneys filter waste from blood, expressed in mL/min/1.73 m². An eGFR above 90 is normal; 60–89 indicates mild reduction; below 60 for three months signals chronic kidney disease (CKD). Our eGFR Calculator uses the CKD-EPI 2021 equation — the current clinical gold standard, now race-free per updated KDIGO guidelines.