Health & Fitness Calculators
BMI, body metrics, and nutrition calculators for health goals.
28 calculators
All calculators
- BMI CalculatorCalculate your Body Mass Index (BMI) from height and weight in metric or imperial units, see your WHO category and healthy weight range.
- Macro CalculatorCalculate your daily calories and macronutrient targets (protein, carbs, and fat) from your body metrics, activity level, and goal.
- Protein CalculatorEstimate your daily protein needs in grams from your body weight and activity goal, shown as a recommended range.
- Body Fat CalculatorEstimate body fat percentage with the US Navy tape method, plus lean mass, fat mass, and where you sit against the standard fitness categories.
- BMR & TDEE CalculatorCalculate your basal metabolic rate and total daily calorie burn from height, weight, age, and activity level — with cutting and bulking targets.
- Pace CalculatorConvert between running pace, speed, distance, and finish time — with per-kilometre splits and predicted times for every standard race distance.
- Calories Burned CalculatorCalculate calories burned walking, running, cycling, or from 20 other activities using MET values — with the net figure above resting burn.
- BAC CalculatorEstimate blood alcohol concentration with the Widmark formula from drinks, body weight, and time — and understand why the number should never decide whether you drive.
- Period CalculatorPredict your next periods, ovulation date, and fertile window from your last period and average cycle length, with a six-cycle calendar.
- Child Height PredictorPredict a child's adult height from the parents' heights using the mid-parental method, with the expected range and how genetics really works.
- Ideal Weight CalculatorEstimate a healthy body weight from height and sex using the Devine, Robinson, Miller, and Hamwi formulas, alongside the healthy-BMI range.
- Water Intake CalculatorEstimate how much water to drink each day based on your body weight, activity level, and climate — with the amount in cups, litres, and ounces.
- Due Date CalculatorEstimate a pregnancy due date from the last menstrual period or conception date, with the current week, trimester, and key milestones.
- One Rep Max CalculatorEstimate your one-rep max (1RM) from a set of several reps using the Epley, Brzycki, and Lombardi formulas, with a training-percentage table for every rep range.
- Target Heart Rate CalculatorFind your training heart-rate zones from your age, using either a percentage of maximum heart rate or the more personal Karvonen heart-rate-reserve method.
- Body Surface Area CalculatorEstimate body surface area (BSA) from height and weight using the Mosteller, Du Bois, and Haycock formulas — the measure clinicians use to scale drug doses.
- Waist-to-Hip Ratio CalculatorCalculate your waist-to-hip ratio and see the WHO health-risk category for your sex — a measure of where you carry fat that BMI cannot capture.
- Calorie Deficit CalculatorEstimate how long it takes to reach a goal weight at a given daily calorie deficit, with the weekly rate of loss and the total energy that has to come from fat.
- Lean Body Mass CalculatorEstimate lean body mass and body-fat percentage from height and weight using the Boer and James formulas, or directly from a measured body-fat percentage.
- Ovulation CalculatorEstimate your ovulation day and fertile window from the first day of your last period and your cycle length, with the next period and test dates.
- Smoking Cost CalculatorCalculate what smoking costs per day, year, and over decades, plus what that money could grow to if invested instead — the financial case for quitting.
- VO2 Max CalculatorEstimate your VO2 max — the top measure of aerobic fitness — from a 12-minute Cooper run test or from your resting and maximum heart rate, with a fitness rating.
- Steps to Miles CalculatorConvert steps into distance in miles and kilometres and estimate calories burned, using a stride length worked out from your height.
- Waist-to-Height Ratio CalculatorCalculate your waist-to-height ratio and see the health-risk category — a simple central-obesity screen behind the rule 'keep your waist under half your height'.
- Pregnancy Weight Gain CalculatorFind the recommended pregnancy weight-gain range from your pre-pregnancy BMI, plus the expected gain by your current week, based on the Institute of Medicine guidelines.
- Race Time PredictorPredict your finishing time at a new race distance from a known time at another, using Riegel's endurance formula, with the equivalent pace.
- Blood Pressure CalculatorClassify a blood pressure reading into the standard categories (normal, elevated, stage 1 or 2 hypertension, crisis), with pulse pressure and mean arterial pressure.
- Cholesterol Ratio CalculatorCalculate your total-to-HDL and LDL-to-HDL cholesterol ratios and non-HDL cholesterol from a lipid panel — better heart-risk indicators than total cholesterol alone.