Health and fitness calculators

Body mass index (BMI) from height and weight in metric or imperial units, with the WHO adult category and the healthy weight range for your height.

Body fat percentage by the US Navy tape method, Jackson-Pollock 3- or 7-site skinfolds, or from BMI, with fat and lean mass and the ACE category.

Ideal body weight (IBW) for your height and sex by the Devine, Robinson, Miller and Hamwi formulas, with the healthy BMI weight range.

Army body fat standard for 2026: your waist-to-height ratio, pass or fail against 0.55 (AD 2026-13), the largest passing waist for your height and margin.

Body surface area (BSA) in m² from height and weight by the Mosteller, DuBois and Haycock formulas, with the spread between them.

Lean body mass (LBM) from height, weight and sex by the Boer, James and Hume formulas, with the implied body fat percentage.

Waist-to-hip ratio and waist-to-height ratio from tape measurements, with the WHO risk cut-offs, the NICE bands and the WHO waist size category.

Basal metabolic rate (BMR) by Mifflin-St Jeor, Harris-Benedict or Katch-McArdle, and daily calorie needs (TDEE) for five activity levels.

Daily calorie target for losing, maintaining or gaining weight, with macros in grams of protein, carbohydrate and fat per day and per meal.

Daily protein intake in grams from body weight, goal and training level, using published g/kg ranges, with a per-meal split.

Daily water intake in litres, glasses and fl oz from body weight, exercise and climate, compared with EFSA and US adequate intakes.

Calories burned by an activity from its MET value in the Compendium of Physical Activities, your body weight and the time spent.

Heart rate zones from your maximum heart rate (220 − age, Tanaka, Gulati for women, or measured) by the Karvonen or percent-of-max method, with a target heart rate.

One-rep max (1RM) from a set of reps with the Epley, Brzycki, Lombardi and O'Conner equations, plus training loads from 50 % to 100 %.

Running pace per km or mile from distance and time, or finish time or distance from pace, with even splits and Riegel race predictions.

Cycling power-to-weight (W/kg), speed and pace, or swimming pace per 100 m and 100 yd with your SWOLF score.

Steps to distance in km and miles from a step length based on your height or measured, with walking time and calories from the ACSM equation.

VO2 max from the Cooper 12-minute run, the Rockport 1-mile walk or the resting heart-rate ratio, rated against Cooper Institute norms for age and sex.

Pregnancy due date from the last period, conception date or IVF transfer, with today's gestational age, trimester and milestones (ACOG).

Estimated conception date and fertile window from a due date, the last period or an ultrasound, with the likely range for each dating method.

Ovulation date, fertile window and next period for the coming cycles, from the first day of your last period and your cycle length.

Next period date and the following 5 predicted periods, with each cycle's fertile window and ovulation day, from your last period and average cycle length.

Recommended pregnancy weight gain by pre-pregnancy BMI (IOM 2009), for singletons or twins, with the weekly rate and a week-by-week chart of your gain.

Blood pressure category (AHA/ACC) for a systolic/diastolic reading, from normal to stage 2 and severe hypertension, with pulse pressure and MAP.

Glucose from mg/dL to mmol/L and back, and HbA1c to estimated average glucose (eAG) and IFCC mmol/mol, with ADA categories.

Dose by weight from a mg/kg rate and body weight, capped at the single and daily maximum, with the liquid volume in mL for a given strength.

eGFR from serum creatinine (mg/dL or µmol/L), age and sex by the race-free CKD-EPI 2021 equation, with optional cystatin C and the KDIGO G1–G5 stage.

Blood alcohol content (BAC) estimate by the Widmark formula from drinks, body weight and time, with the elimination curve and time back to zero.

How much caffeine is left in your body from up to three doses, based on its half-life, and when the level drops below an amount you choose.

Bedtimes for a wake-up time, or wake-up times for a bedtime, counted in 90-minute sleep cycles plus the time it takes to fall asleep.