Health calculators
Estimate BMI, calories, and other everyday health numbers.
Weight and body composition
BMI calculator
Work out your Body Mass Index from your height and weight, in metric or imperial units, and see the WHO weight category.
BMI calculator for children
Work out a child's BMI from weight and height, with age and sex noted because child BMI is read against percentile growth charts.
Body fat calculator
Estimate your body-fat percentage with the US Navy tape method, plus your fat and lean mass and a fitness category.
Ideal weight calculator
Estimate your ideal body weight from your height and sex using the classic formulas, alongside the healthy BMI weight range.
Waist-to-hip ratio calculator
Work out your waist-to-hip ratio from your waist and hip measurements and see the WHO health-risk category for your sex.
Weight loss calculator
Work out the weekly rate and daily calorie deficit needed to reach a goal weight in a set number of weeks.
GLP-1 weight loss calculator
Project weight loss on a GLP-1 medication from your starting weight and time on treatment, using clinical-trial averages. Informational only.
Calories and nutrition
Calorie calculator
Work out your daily calorie target from your body details, activity level, and goal — maintain, lose, or gain.
BMR calculator
Estimate your basal metabolic rate — the calories your body burns at rest — from your weight, height, age, and sex using the Mifflin-St Jeor equation.
TDEE calculator
Estimate your Total Daily Energy Expenditure and maintenance calories from your BMR and activity level.
Macro calculator
Split a daily calorie target into grams of protein, carbs, and fat using a balanced, low-carb, or high-protein ratio.
Protein intake calculator
Estimate your daily protein in grams from your body weight and goal, with a per-meal split across four meals.
Daily Water Intake Calculator
Estimate how much water you should drink each day based on your body weight and activity level.
Pregnancy and family
Pregnancy due date calculator
Estimate your due date with Naegele's rule from the first day of your last period, plus conception and third-trimester dates.
Ovulation calculator
Estimate your ovulation day and fertile window from the first day of your last period and your average cycle length.
Height calculator
Predict a child's adult height from the parents' heights using the mid-parental method, with a typical range.
Fitness and training
Everyday health
Age Calculator
Find out exactly how old you are in years, months, days, and total days from any date of birth.
Life expectancy calculator
Get a rough life expectancy estimate from your age, sex, and a few lifestyle factors. A simplified illustration, not a forecast.
Sleep calculator
Find the best times to go to bed for a chosen wake-up time, based on 90-minute sleep cycles, so you wake at the end of a cycle.
BAC calculator
Estimate blood alcohol concentration with the Widmark formula from standard drinks, body weight, sex, and time. An estimate only — never drink and drive.
Carbon footprint calculator
Estimate your yearly carbon footprint from driving, flights, electricity, and diet — with a monthly figure and trees needed to offset it.
Days until calculator
Count down the days until any date. Pick a date and see the days remaining, the weeks and days, and which weekday it falls on.