Body Metric Calculators
A hundred body numbers — BMI, BMR, heart rate zones, blood pressure markers
🩺 For reference only — diagnosis and treatment belong to your clinician.
Weight & Shape20
BMI CalculatorGet your body mass index and ideal weight from height and weight.Ideal Weight CalculatorSee ideal weight at BMI 22 alongside the clinical Devine formula.Target Weight for a BMIWork backwards from a BMI goal to the weight it requires.Body Fat (Navy Method)Estimate body fat percentage using only a tape measure.Lean Body MassGet lean mass — muscle and bone — from weight and body fat percentage.Waist-to-Hip RatioCheck whether fat is concentrated around your abdomen.Waist-to-Height RatioCheck whether your waist is more than half your height.Body Surface AreaCalculate BSA — used for chemotherapy dosing — with both Du Bois and Mosteller.Ponderal IndexA height-cubed index that corrects BMI at extreme heights.Adjusted Body WeightCompute the adjusted weight used for drug dosing in obesity.BMI PrimeBMI divided by the overweight cut-off, so one is the line.Healthy Weight RangeThe weight band that puts your BMI in the normal range.Target Waist SizeKeep your waist under half your height.Body Fat from BMIEstimate body fat percentage from BMI, age and sex alone.FFMI (Fat-Free Mass Index)Divide your fat-free weight by height to gauge muscle.Weight Change PercentageHow much your weight moved in percent, and the weekly pace.Body Frame SizeDivide height by wrist circumference to gauge how heavy your skeleton is.Skeletal Muscle Index (Estimate)Limb muscle divided by height, to spot muscle shortfall.Broca Index Ideal WeightThe classic “height minus 100, times a factor” reference weight.Waist, Chest & Hip RatiosRead your shape from three circumferences.
Metabolism & Calories20
BMR CalculatorFind the minimum calories your body burns doing nothing at all.BMR from Lean MassThe Katch-McArdle formula, more accurate when you know your body fat.TDEE CalculatorMultiply BMR by an activity factor for total daily calories burned.Calorie Deficit CalculatorSet daily intake to match the rate of weight loss you want.Weight Loss TimelineSee how many weeks reaching your goal weight will take.Protein RequirementWork out daily protein from a target per kilogram of body weight.Daily Water IntakeEstimate how much water to drink from body weight and exercise time.Macro Split CalculatorTurn a daily calorie target into grams of carbs, protein and fat.MET Calorie BurnCalculate calories burned from exercise intensity (MET) and duration.Steps to CaloriesConvert step count and stride into distance walked and calories burned.BMR (Mifflin–St Jeor)The most widely used formula for daily resting calories.Weight Gain from a SurplusHow fast you gain from a given daily calorie surplus.Weekly Loss Target to Daily DeficitThe daily cut needed for a given weekly weight loss.Time to Burn a Food’s CaloriesHow many minutes of exercise a snack costs.BMR per KilogramDivide resting calories by weight to see how active your metabolism runs.Protein per MealSplit your daily protein across meals.Daily Fibre TargetScale your fibre goal to how much you eat.Added Sugar LimitTurn a percentage-of-calories sugar cap into grams.Sodium to Salt ConverterTurn the sodium on a label into grams of salt.Daily Caffeine CeilingYour caffeine limit by body weight, in milligrams and cups.
Heart & Exercise20
Max Heart RateEstimate maximum heart rate from age using Tanaka and 220−age.Target Heart Rate (Karvonen)Get training zones that account for your resting heart rate.Cooper Test VO2maxEstimate maximal oxygen uptake from how far you run in 12 minutes.VO2max from Resting HRRough cardiorespiratory fitness estimate with no running required.One-Rep Max CalculatorEstimate your single-rep maximum from a set you completed.Weight for Target RepsWork back from your 1RM to the load for a given rep count.Running Pace CalculatorGet pace per kilometre and speed from a distance and a time.Race Finish TimeSee your finishing time for a target pace and distance.Treadmill Speed to PaceConvert a treadmill speed in km/h into pace per kilometre.Swim Pace per 100 mGet your per-100-metre split from a swim distance and time.Karvonen Target Heart RateA target zone that accounts for your resting heart rate.Heart Rate RecoveryHow far your pulse falls in the minute after you stop.Maximum Heart Rate (Tanaka)A better estimate than subtracting your age from 220.Step Count to CaloriesTurn a step count and your weight into calories and distance.VO2max to METsConvert cardio capacity into units of exercise intensity.Cycling Speed from CadenceWork out speed from pedal rpm and gear ratio.Rowing 500 m SplitTurn a distance and a time into pace per 500 metres.Training VolumeWeight × reps × sets — the total load of an exercise.RPE to Percentage of 1RMEstimate what share of your max a set at a given RPE represents.Marathon Time from a HalfPredict a full marathon finish from your half-marathon time.
Children & Growth12
Child's Predicted HeightEstimate a child’s adult height from the parents’ heights.Newborn Feeding AmountGet daily formula volume and per-feed amount from a baby’s weight.Newborn Weight GainCompare current weight against birth weight as a percentage.Paediatric Dose by WeightCompute a single dose and daily total from a mg/kg figure.Blood Volume CalculatorEstimate total blood volume from body weight.Annual Growth RateConvert two height measurements into centimetres gained per year.Child’s Daily Fluid NeedDaily fluid requirement from a child’s weight.Child’s Daily Calorie NeedEstimate daily calories from a child’s age and weight.Growth VelocityHow many centimetres a year from two height measurements.Formula Volume per KilogramDaily and per-feed formula from a baby’s weight.Child Fever Medicine Dose by WeightPer-dose and daily totals from weight and mg per kilogram.Corrected Age for Preterm BabiesAdjust a baby’s age for how early they arrived.
Health Markers16
Mean Arterial PressureGet MAP and pulse pressure from systolic and diastolic readings.Pulse PressureThe gap between your systolic and diastolic readings.Cholesterol RatioTotal cholesterol divided by HDL — a cardiovascular risk marker.LDL Cholesterol (Friedewald)Calculate LDL from the three numbers on your lipid panel.Non-HDL CholesterolTotal minus HDL — every atherogenic lipid added together.HOMA-IR Insulin ResistanceCalculate insulin resistance from fasting glucose and fasting insulin.HbA1c to Average GlucoseConvert HbA1c into the average blood glucose of the last 2–3 months.BSA-Based Drug DoseCompute a dose from a per-square-metre figure and body surface area.eGFR Kidney FunctionEstimated filtration rate from creatinine, age and sex.Creatinine Clearance (Cockcroft–Gault)Kidney clearance that takes body weight into account.Triglyceride to HDL RatioDivide triglycerides by HDL for a metabolic read.QUICKI Insulin Sensitivity IndexInsulin sensitivity from fasting glucose and insulin.TyG IndexGauge insulin resistance from triglycerides and glucose alone.FIB-4 Liver Fibrosis IndexGauge fibrosis risk from age, liver enzymes and platelets.Remnant CholesterolTotal cholesterol minus HDL and LDL — what is left over.HbA1c Unit Converter (% ↔ IFCC)Convert between NGSP percent and IFCC mmol/mol.
Daily Metabolism12
Glucose Units (mg/dL ↔ mmol/L)Convert blood glucose between US and European units.Cholesterol Unit ConverterConvert cholesterol and triglycerides from mg/dL to mmol/L.Sleep Cycle CalculatorPlan sleep in 90-minute cycles so you wake between them.Blood Alcohol EstimatorEstimate BAC from the volume and strength of what you drank (Widmark).Alcohol Clearance TimeEstimate how long until your blood alcohol reaches zero.Caffeine RemainingSee how much caffeine is still in you hours after a coffee.Sleep DebtHow many hours of sleep you have fallen behind over several days.Jet Lag Adjustment DaysEstimate how long adaptation takes from the time shift and direction.Standard Drinks CalculatorGrams of pure alcohol and standard drinks from volume and strength.Smoking Pack-YearsCumulative tobacco exposure from cigarettes a day and years smoked.Sweat RateHourly fluid loss from weight change across a session.Calories in a DrinkEnergy from the alcohol itself, from volume and strength.
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.