Health & Fitness calculators
Body metrics, calories, hydration and training
- BMI Calculator Body mass index and healthy weight range
- BMR Calculator Calories your body burns at rest
- Body Fat Calculator Body fat from tape measurements
- Calorie Calculator Daily calories to maintain, lose or gain
- Heart Rate Zones Calculator Training zones from your maximum heart rate
- Ideal Weight Calculator Devine, Robinson, Miller and Hamwi estimates
- Macro Calculator Protein, carb and fat grams from daily calories
- One Rep Max Calculator Max strength estimate from any rep set
- Pregnancy Due Date Calculator Due date from LMP, conception or IVF
- Running Pace Calculator Pace per km and mile from time
- Sleep Calculator Bedtimes and wake times from 90-minute cycles
- Water Intake Calculator Daily water target from weight and exercise
Which health calculator to use
For body measurements, the BMI calculator places a height and weight in the WHO categories and gives the healthy weight range for your height. The body fat calculator estimates body fat from tape measurements, and the ideal weight calculator puts four published formulas side by side.
For energy and diet, three calculators build on each other. The BMR calculator estimates the calories your body burns at complete rest with the Mifflin-St Jeor equation. The calorie calculator multiplies that by an activity factor to give daily targets for maintaining, losing or gaining weight, and the macro calculator splits a daily calorie figure into grams of protein, carbohydrate and fat.
For training and daily routines, there are calculators for heart rate zones, running pace, one rep max, sleep cycles and water intake, plus a pregnancy due date calculator that works from the last period, the conception date or an IVF transfer. Every result here is an estimate from a population formula, and each page names its formula and works an example through it. Treat the numbers as a starting point to discuss with a doctor, dietitian or coach, not as a diagnosis.