Health calculators

Health estimates need visible assumptions. This hub keeps BMI, nutrition, pregnancy and body calculators together with formulas, source notes and human limits.

HealthBMI Calculator - Adult Body Mass Index, Healthy Weight Range & BMI PrimeCalculate adult BMI from metric or US units, see the BMI category, healthy weight range, BMI Prime, Ponderal Index and clear health limitations.Health & FitnessBMR CalculatorEstimate basal metabolic rate using Mifflin-St Jeor or revised Harris-Benedict, with activity-adjusted daily context.Health & FitnessBody Fat Percentage CalculatorEstimate body fat percentage from circumference measurements using the U.S. Navy method for adults.Health & FitnessCalorie Deficit / TDEE CalculatorEstimate BMR, total daily energy expenditure and a calorie target for weight maintenance, loss or gain.Health & BodyConception Date CalculatorEstimate conception date and fertile-window timing from due date, last menstrual period or ultrasound gestational age, with clear medical limitations.Freight & LogisticsDimensional Weight CalculatorCalculate freight chargeable weight from parcel dimensions, actual weight and carrier divisor.Health & FitnessIdeal Body Weight CalculatorEstimate ideal body weight using Devine and Hamwi-style adult formulas, with BMI-range cross-checks.Unit ConversionKilograms to Pounds CalculatorConvert kilograms to pounds with an optional packing or tolerance allowance kept separate from the measured weight.Health & FitnessMacro CalculatorSplit a daily calorie target into protein, fat and carbohydrate grams using body weight and selected macro percentages.Health & FitnessMax HR / Target Heart Rate Zones CalculatorEstimate maximum heart rate and target training zones using age, resting heart rate and intensity bands.Medical / HealthcareNurse Staffing Ratio CalculatorEstimate nurses required per shift and per day from patient count, staffing ratio and daily shift count.Health & LifecycleOvulation / Fertility CalculatorEstimate ovulation date, fertile window and next period from last menstrual period, cycle length and luteal phase.Unit ConversionPounds to Kilograms CalculatorConvert pounds to kilograms with an optional tolerance or packing allowance kept separate from the measured weight.Health & LifecyclePregnancy Due Date CalculatorEstimate due date, gestational age and trimester from last menstrual period, conception, IVF transfer or ultrasound dating.Unit ConversionStone to Kilograms CalculatorConvert stone and pounds into kilograms using the exact international pound definition, with an optional allowance kept separate for records and worksheets.Health & FitnessWater Intake CalculatorEstimate a daily water target from body weight, exercise minutes, climate adjustment and pregnancy/breastfeeding context.Study & SchoolWeighted Average CalculatorCalculate a weighted mean from values and weights for grade categories, credits, survey scores, index components and spreadsheet checks, with contribution lines, total-weight warnings and a printable weighted-average worksheet record.