Free health and everyday calculators

These free calculators estimate your BMI, daily calories, due date or ovulation window, and convert units, temperatures, shoe sizes and recipes. They give you useful benchmarks, not a diagnosis, and they are not a substitute for medical advice.

✅ Free
🔒 No sign-up
📱 Works on mobile
⚡ Instant results

BMI calculatorBMI, WHO category, visual gauge and healthy weight range for your height.Calorie calculatorBMR, daily calorie needs and targets to lose or gain weight.Ideal weight calculatorIdeal body weight by Devine, Robinson, Lorentz and BMI 22, plus your healthy range.Due date calculatorEstimated due date, gestational age, trimesters and key pregnancy dates.Ovulation calculatorOvulation date, fertile window and next period based on your cycle length.Body fat calculatorBody fat percentage with the US Navy tape method or BMI (Deurenberg).Water intake calculatorHow much water to drink a day based on weight, exercise and heat.BAC calculatorEstimate your blood alcohol content (Widmark) and the time to reach zero.Square footage and materialsRoom square footage, gallons of paint, tile and flooring to buy.Unit converterLength, weight, volume, speed and area: convert metric and imperial units.Fahrenheit to Celsius converterConvert Fahrenheit, Celsius and Kelvin in both directions.Shoe size converterEU, UK and US shoe sizes for men, women and kids, from foot length.Clothing size chartUS, UK, EU and FR clothing sizes for women, men and kids from your measurements.Recipe converterCups, spoons, grams and ounces, plus scaling a recipe to more or fewer servings.