Health & Fitness Calculators

Calculate body mass index, see your category, and find the weight range that would put you in the healthy band.

Estimate body fat percentage with the US Navy circumference method, plus lean mass and category.

Find your BMR, maintenance calories, and daily targets for losing, maintaining, or gaining weight.

Calculate your five training zones from maximum and resting heart rate using the Karvonen method.

Compare the four classic ideal body weight formulas against the healthy BMI range for your height.

Estimate lean mass and fat mass from height and weight alone, using the Boer, James and Hume formulas.

Split your calorie target into protein, carbohydrate, and fat grams for your goal and training style.

Estimate your 1RM from a set you have actually done, compare the major formulas, and get your training percentages.

Find your likely fertile window and next few cycles from your last period and typical cycle length.

Work out an estimated due date from your last period, conception date, or IVF transfer, with a full milestone timeline.

Find your daily protein target based on body weight, goal, and training volume — with per-meal distribution.

Convert between pace, speed, and finish time, and get equivalent race predictions and training paces.

Find bedtimes and wake times that land between sleep cycles, so you wake in light sleep instead of deep sleep.

Estimate daily fluid needs based on body weight, activity, climate, and exercise duration.