Health & Fitness Calculators — Free Online

BMI Calculator Calculate your Body Mass Index and see which category it falls in.

Calorie (TDEE) Calculator Estimate the daily calories you burn and how much to eat to lose or gain weight.

Body Fat Calculator Estimate your body fat percentage with the U.S. Navy tape method.

Ideal Weight Calculator Find a healthy target weight range for your height and sex.

Water Intake Calculator Estimate how much water to drink each day for your weight and activity.

BMR Calculator Calculate your Basal Metabolic Rate — the calories you burn at rest.

Running Pace Calculator Work out your running pace and speed from distance and time.

Macro Calculator Split a daily calorie target into protein, carbohydrate and fat grams.

Calorie Deficit Calculator Find the daily calories to hit a target weekly weight-loss rate.

Protein Intake Calculator Estimate your daily protein target in grams from body weight and goal.

One Rep Max Calculator Estimate your 1RM from a weight and reps, with a percentage training table.

Maximum Heart Rate Calculator Estimate your maximum heart rate from your age.

Heart Rate Zone Calculator Calculate your five training heart-rate zones from age and resting heart rate.

Blood Alcohol (BAC) Calculator Estimate blood alcohol concentration from drinks, body weight and time.

Pregnancy Due Date Calculator Estimate your due date and how many weeks pregnant you are from your last period.

Ovulation & Fertility Calculator Estimate your ovulation day and fertile window from your last period.

Waist-to-Hip Ratio Calculator Calculate your waist-to-hip ratio and see the associated health risk band.

Waist-to-Height Ratio Calculator Calculate your waist-to-height ratio — a simple central-obesity screen.

Lean Body Mass Calculator Estimate your lean body mass and fat mass using the Boer formula.

Army Body Fat Calculator Estimate body fat with the U.S. Army (AR 600-9) tape method and check the standard.

Calories Burned Calculator Estimate calories burned in an activity from its MET value, your weight and time.

Steps to Miles Calculator Convert step count into miles and kilometres using your height and pace.

Sleep Cycle Calculator Find the best bedtimes or wake times based on 90-minute sleep cycles.

Body Surface Area Calculator Calculate body surface area (BSA) with the Mosteller and Du Bois formulas.

Period Calculator Predict your next few periods, ovulation and fertile window from your last period.

Conception Date Calculator Estimate the date of conception from a due date or your last menstrual period.

Pregnancy Weight Gain Calculator Recommended pregnancy weight-gain range for your week, based on pre-pregnancy BMI.

GFR Calculator (eGFR, CKD-EPI) Estimate kidney function (eGFR) from creatinine, age and sex, with the CKD stage.