Calculates Basal Metabolic Rate using the Mifflin-St Jeor equation with age, sex, height, and weight. Nutritionists use it for diet planning. Health data never leaves your device — every calculation runs locally in your browser.
Content reviewed October 2026 · About Toolzum
Calculate your daily calorie needs from BMR (Mifflin-St Jeor) times activity level. Shows basal burn plus maintenance calories for fitness planning. Health data never leaves your device — every calculation runs locally in your browser.
Compare baby weight and height against WHO median references by age and sex, shown as % above or below the median — a reference comparison, not clinical percentiles. Monitor your childs growth compared to population medians. Health data never leaves your device — every calculation runs locally in your browser.
Computes Body Mass Index from metric or imperial height and weight inputs, categorizing the result into underweight, normal, overweight, and obese, with a healthy weight range for your height. Health data never leaves your device — every calculation runs locally in your browser.
Calculate customer churn rate by dividing customers lost by total customers. Monitor retention health for your subscription business. Numbers never leave your device — every calculation runs locally in your browser.
Computes exact age in years, months, and days from a given birth date relative to any target date. Numbers never leave your device — every calculation runs locally in your browser.
Basal Metabolic Rate — calories your body burns at complete rest in 24h. Example: a 30-year-old man, 178cm, 75kg → ≈1,718 kcal/day (10×75 + 6.25×178 − 5×30 + 5). Everything above that (movement, digestion, exercise) adds on top. Defaults (male, 25, 70 kg, 170 cm, sedentary) give BMR ≈1,643 and TDEE ≈1,971.
Mifflin-St Jeor (men: 10w + 6.25h − 5a + 5; women: −161 instead of +5) validates better against modern calorimetry, underestimating less for overweight users. This tool uses Mifflin-St Jeor.
Never eat at BMR long-term — that is starvation level. Multiply BMR by activity (sedentary 1.2 … very active 1.9) to get TDEE, then subtract 300–500 kcal for fat loss. Use the calorie calculator for the full chain.
Yes, ~6 kcal/lb/day vs ~2 for fat — but the effect is modest: 5kg of extra muscle adds roughly 60–70 kcal/day. Strength training matters more for the calories it burns directly.
No. All calculations run locally in your browser. No health data is transmitted or stored.
TDEE Calculator
Calculate your Total Daily Energy Expenditure (TDEE) from BMR and activity level. Find how many calories you burn per day.
Daily Calorie Needs
Calculate your daily calorie needs from BMR (Mifflin-St Jeor) times activity level. Shows basal burn plus maintenance calories for fitness planning. Health data never leaves your device — every calculation runs locally in your browser.