Accurate, science-backed calculators for BMI, calories, pregnancy, sleep, body fat, and 19 more health metrics. Free forever. No sign-up required.
Browse 24 free calculators across 5 categories — all based on clinically validated methods
Calculate your Body Mass Index and find your healthy weight range. Metric & imperial with WHO categories.
Find your healthy weight range using 5 proven medical formulas based on height, sex, and frame size.
Estimate your body fat percentage using the US Navy circumference method. Get fat mass and lean mass.
Calculate your WHR and body shape type. Check cardiovascular health risk per WHO guidelines.
Determine if you have a small, medium, or large body frame using wrist circumference measurements.
Calculate your exact age in years, months, and days. Find next birthday, age difference, and future age.
Find your Total Daily Energy Expenditure. Calculate calories to lose, maintain, or gain weight.
Calculate your ideal daily protein intake for muscle building, weight loss, or general health.
Find out how many liters of water you need daily based on weight, activity, and climate.
Calculate perfect daily macros — protein, carbs, and fat — tailored to your body and fitness goals.
Calculate exactly how many calories to eat to reach your goal weight by your target date.
Calculate your Basal Metabolic Rate using 4 proven formulas. Compare Mifflin, Harris-Benedict, and more.
Calculate your 5 target heart rate zones for fat burning, cardio, and peak performance training.
Calculate pace, finish time, or distance. Get race predictions for 5K, 10K, half, and full marathon.
Convert daily steps to calories burned, distance, and miles walked based on your weight and stride.
Find the best time to wake up based on 90-minute sleep cycles. Wake refreshed, not groggy.
Calculate your estimated due date from last period, conception date, or IVF transfer. Track trimesters.
Find your fertile window and ovulation date with a 3-month cycle forecast and calendar view.
Predict your child's adult height based on parents' heights using the Mid-Parental Height formula.
Check if your BP reading is normal, elevated, or high. Based on AHA guidelines with instant advice.
Convert blood glucose between mg/dL and mmol/L. Includes HbA1c converter and normal range chart.
Assess your 10-year risk of Type 2 diabetes with the validated FINDRISC questionnaire. Takes 2 minutes.
Estimate your Vitamin D deficiency risk based on location, skin tone, and sun exposure habits.
Calculate alcohol units in your drinks and check against weekly safe limits. NHS & WHO guidelines.