Health calculators
Ten calculators for body measurements, nutrition, pregnancy, fitness and sleep, based on widely published formulas.
- BMI CalculatorBody mass index and healthy weight range.
- Calorie CalculatorDaily calorie needs and weight-change targets.
- Body Fat CalculatorEstimate body fat percentage with a tape measure.
- Water Intake CalculatorDaily water needs from weight, exercise and climate.
- Sleep CalculatorBedtimes and wake times based on 90-minute cycles.
- Ideal Weight CalculatorIdeal body weight by four classic formulas.
- Macro CalculatorDaily grams of protein, carbs and fat.
- Pregnancy Due Date CalculatorDue date, weeks pregnant and trimester dates.
- Heart Rate Zones CalculatorMax heart rate and five training zones.
- Running Pace CalculatorPace, finish time and distance for runners.
These tools give estimates using formulas from health organizations and published research. An estimate is a starting point for your own planning, not a diagnosis.
If you have a medical condition, are pregnant, or are about to make a big change to your diet or exercise, talk to a doctor or registered dietitian first. Every calculator here works in metric and imperial units.
Which tool should I use?
- Want to know where your weight sits for your height? BMI Calculator. Get your BMI, the WHO category and your healthy weight range.
- Planning to lose, gain or maintain weight? Calorie Calculator. Estimate daily calories and targets for a steady pace.
- Tracking body composition? Body Fat Calculator. Estimate body fat percentage from a tape measure.
- Not sure how much to drink? Water Intake Calculator. Find a daily target from weight, exercise and climate.
- Trying to wake up less tired? Sleep Calculator. Find bedtimes that match 90-minute sleep cycles.
- Wondering what you should weigh? Ideal Weight Calculator. Four classic formulas and a healthy BMI range.
- Planning your meals? Macro Calculator. Turn calories into grams of protein, carbs and fat.
- Expecting a baby? Pregnancy Due Date Calculator. Due date, weeks pregnant and trimester dates.
- Training by heart rate? Heart Rate Zones Calculator. Maximum heart rate and five training zones.
- Running a race? Running Pace Calculator. Pace, finish time and distance in km or miles.
Guides for these tools
- BMI Explained: Categories, Limits and Alternatives. What BMI measures, what it misses and how to use it sensibly.