Health & Fitness
Body measurements, energy needs, training and pacing. Population-level estimates with their formulas and limits explained — not diagnoses.
- BMI CalculatorCalculate body mass index (BMI) in metric or imperial units and see the WHO adult category, with the limits of BMI explained.
- BMR CalculatorEstimate basal metabolic rate (BMR) with the Mifflin–St Jeor, revised Harris–Benedict or Katch–McArdle equation.
- TDEE CalculatorEstimate total daily energy expenditure (TDEE) — your maintenance calories — from BMR and an activity multiplier.
- Daily Calorie Needs EstimatorEstimate daily calories to maintain weight and for moderate weight loss or gain, with safety flags for very low intakes.
- Calorie Deficit EstimatorEstimate how long it takes to reach a goal weight with a daily calorie deficit, with warnings for unsafe deficits or intakes.
- Calorie Surplus EstimatorPlan a modest calorie surplus for gradual weight or muscle gain, with daily intake and an estimated timeline.
- Macronutrient CalculatorSplit daily calories into grams of protein, carbohydrate and fat using a preset or custom percentages.
- Protein Intake EstimatorEstimate daily protein needs in grams from body weight and activity, from the RDA baseline to athletic ranges.
- Body Fat Percentage EstimatorEstimate body fat percentage with the US Navy circumference method from height, neck, waist and (for women) hip measurements.
- Lean Body Mass CalculatorEstimate lean body mass with the Boer, James or Hume formulas, or from a known body fat percentage.
- Ideal Weight Estimation CalculatorCompare ideal body weight estimates from the Devine, Robinson, Miller and Hamwi formulas with the healthy BMI weight range.
- Waist-to-Height Ratio CalculatorCalculate waist-to-height ratio (WHtR), a simple indicator of central fat linked to cardiometabolic risk.
- Waist-to-Hip Ratio CalculatorCalculate waist-to-hip ratio (WHR) and compare it with WHO cut-offs for increased metabolic risk.
- Healthy BMI Weight Range CalculatorFind the weight range that corresponds to a healthy adult BMI (18.5–24.9) for your height, in kg or lb.
- Water Intake Estimation CalculatorEstimate daily water needs from official adequate-intake reference values plus extra for exercise sweat losses.
- Heart Rate Zone CalculatorCalculate five heart rate training zones from an estimated or measured maximum, using heart-rate reserve (Karvonen) or percent of max.
- Target Heart Rate CalculatorFind your target heart rate for a chosen intensity and the moderate and vigorous exercise ranges for your age.
- Running Pace CalculatorCalculate running pace per kilometre and per mile and speed in km/h and mph from distance and finish time.
- Running Speed CalculatorConvert running pace to speed (km/h and mph) and back, with finish times for 5K, 10K, half marathon and marathon.
- Race Time Prediction CalculatorPredict race times at other distances from a recent result using Riegel’s endurance formula.
- Cycling Speed CalculatorCalculate cycling speed from gearing (chainring, cog, wheel size) and cadence, or average speed from distance and time.
- Walking Pace CalculatorTurn walking cadence and step length into speed, pace per kilometre, time for a distance and an intensity guide.
- Step Distance CalculatorConvert a step count into distance in kilometres and miles using your step length or an estimate from height.
- Exercise Calorie Estimation CalculatorEstimate calories burned during exercise from MET values in the Compendium of Physical Activities, body weight and duration.
- One-Repetition Maximum (1RM) EstimatorEstimate your one-rep max (1RM) from a submaximal set with the Epley, Brzycki and Lombardi formulas, plus a percentage table.
- Training Volume CalculatorCalculate total training volume (sets × reps × weight), total sets and reps for a workout.
- Pregnancy Due Date EstimatorEstimate a pregnancy due date from the last menstrual period (adjusted for cycle length), conception date or IVF transfer date.
- Pregnancy Week CalculatorFind how many weeks and days pregnant you are on a given date, the trimester and days until the due date.
- Sleep Duration CalculatorCalculate how long you slept from bedtime and wake time, minus time to fall asleep, and compare it with recommended ranges by age.
- Sleep Cycle Planning CalculatorPlan bedtimes or wake-up times around roughly 90-minute sleep cycles, allowing for time to fall asleep.
Health results are general estimates for adults and do not replace medical advice, diagnosis or treatment. Speak to a qualified health professional about your personal situation, especially during pregnancy or if you have a medical condition.