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 & Shape27
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.Body Roundness IndexTurn height and waist alone into a single number for how round the torso is.Relative Fat MassEstimate body fat with a tape measure alone — height and waist are all it needs.Skinfold Body Fat CalculatorBody fat from the sum of three caliper measurements.Weight at a Target Body FatThe weight you would reach at a target body fat, holding lean mass steady.Pregnancy Weight Gain CalculatorThe recommended gain range for a pre-pregnancy BMI at your current week.Total Body Water CalculatorLitres of water in the body, and what share of body weight that is.Waist Circumference Risk CalculatorYour waist against the sex-specific lines: 94 and 102 cm for men, 80 and 88 for women.
Metabolism & Calories26
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.Calories per MealSplit a daily calorie target across the number of meals you actually eat.Share of Your Daily CaloriesSee what slice of the day one food takes out of your calorie target.Net Carbs CalculatorTotal carbs minus fibre and sugar alcohols — what your body actually absorbs.Glycaemic Load CalculatorGlycaemic index multiplied by the carbohydrate you actually eat.Calorie Density CalculatorCalories per 100 g, and how many grams make up 200 kcal.Metabolic Age CalculatorYour composition-based BMR laid over the average BMR curve by age.
Heart & Exercise27
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.Stride Length from HeightTurning steps into distance needs a stride length; estimate one from height.VO2max from Running SpeedEstimate maximal oxygen uptake from the pace you can hold on the flat.Power-to-Weight CalculatorCycling power divided by body weight — the number that decides climbs.Critical Swim Speed CalculatorYour sustainable 100 m pace from a 400 m and a 200 m time trial.Negative Split Pacing CalculatorSplit a goal time so the second half comes in slightly faster.Steps to Distance CalculatorSteps times stride length, in kilometres and miles.Rockport Walk Test CalculatorVO₂max from a brisk one-mile walk: your time and your heart rate at the finish.
Children & Growth14
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.Child Weight from AgeEstimate a child's weight from age alone when there is no scale to hand.Sleep Needed by AgeHow much sleep a child needs each day at a given age.
Health Markers40
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.LDL to HDL RatioDivide the harmful cholesterol by the protective kind.Uric Acid LevelWhich band a check-up uric acid reading falls into, by sex.Vitamin D LevelWhich band a blood vitamin D (25-OH-D) reading falls into, with the unit converted too.Ferritin LevelWhich band a ferritin (stored iron) reading falls into, by sex.TSH (Thyroid) LevelWhether a TSH reading points to normal, overactive or underactive thyroid.Hemoglobin LevelWhether a hemoglobin reading falls into anemia, normal or high, by sex.Calcium LevelWhether a blood calcium reading is low, normal or high.Potassium LevelWhether a blood potassium reading is low, normal or high.CRP (C-Reactive Protein) LevelWhich band a CRP reading falls into.Vitamin B12 LevelWhich band a blood vitamin B12 reading falls into.Cortisol LevelWhich band a morning fasting cortisol reading falls into.Sodium LevelWhether a blood sodium reading is low, normal or high.Magnesium LevelWhether a blood magnesium reading is low, normal or high.Testosterone LevelWhich band a blood testosterone reading falls into (adult male reference).Folate LevelWhich band a blood folate (vitamin B9) reading falls into.Free T4 LevelWhich band a blood free T4 (thyroid hormone) reading falls into.Iron / TIBC (Transferrin Saturation)Transferrin saturation from serum iron and total iron-binding capacity.Vitamin B6 LevelWhether a blood vitamin B6 reading is low, normal or high.Ankle-Brachial Index (ABI)Leg blood-flow status from ankle and arm systolic pressure.Grip Strength AsymmetryPercentage difference between your two hands’ grip strength.Bone Density T-ScoreWhich band a DEXA bone-density T-score falls into.Blood Pressure CategoryWhich stage a systolic and diastolic reading falls into.Chronic Kidney Disease StageWhich stage from G1 to G5 an eGFR value falls into.Grip Strength Norm CalculatorYour dynamometer reading against the sarcopenia screening cut-offs: 27 kg for men, 16 kg for women.
Daily Metabolism16
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.Last Coffee of the DayWork backwards from how little caffeine you want left at bedtime to when the last cup should be.Sleep EfficiencySee how much of the time you spent in bed you were actually asleep.Nap Length CalculatorWhether your planned nap ends at a point you can wake up clear.Sweat Loss Percentage CalculatorWhat share of body mass a session cost you, measured against the 2% threshold.
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.