Health Calculators
17 free calculators
Science-backed health metrics and body composition calculators.
BMI Calculator
Calculate your Body Mass Index using the WHO standard formula. Get your weight category and healthy weight range instantly.
BMI = weight(kg) / height(m)²
Ideal Weight Calculator
Find your healthy weight range based on height, age, and gender using multiple validated formulas.
Hamwi / Robinson / Miller / Devine formulas
Body Fat Calculator
Estimate your body fat percentage using the US Navy method or BMI-based method.
US Navy Circumference Method
BMI Prime Calculator
Calculate your BMI Prime — a ratio of your BMI to the upper ideal BMI of 25.
BMI Prime = BMI ÷ 25
Navy Body Fat Calculator
Calculate body fat percentage using the official US Navy circumference measurement method.
US Navy Circumference Method
Waist to Hip Ratio Calculator
Calculate your waist-to-hip ratio to assess cardiovascular and metabolic health risk.
WHR = waist ÷ hip
Body Shape Calculator
Determine your body shape (apple, pear, hourglass, rectangle) from measurements.
Bust:Waist:Hip ratio analysis
Body Surface Area Calculator
Calculate body surface area (BSA) using the DuBois, Mosteller, and Haycock formulas.
Mosteller: BSA = √(H × W / 3600)
Blood Pressure Calculator
Compare a blood pressure reading with published category thresholds. This educational tool cannot diagnose hypertension.
AHA Blood Pressure Classification
Cholesterol Calculator
Compare cholesterol values with general reference ranges. This does not calculate or diagnose cardiovascular risk.
AHA Cholesterol Classification + LDL/HDL ratio
Vitamin D Calculator
Explore factors associated with vitamin D and compare the result with general NHS guidance. Not a dose recommendation or deficiency test.
Educational risk-factor model; not a validated dosing formula
Body Measurements Calculator
Calculate and track key body measurements including lean mass, body fat, and shape ratios.
Multiple measurement formulas
Waist-to-Height Ratio Calculator
Calculate your waist-to-height ratio — a powerful predictor of cardiovascular and metabolic disease risk that outperforms BMI for detecting central obesity.
WHtR = waist (cm) ÷ height (cm)
Healthy Weight Calculator
Find your healthy weight range using 5 validated methods — BMI range, Hamwi, Devine, Robinson, and Miller formulas — with frame size adjustments.
Hamwi + Devine + BMI range composite
BMI Calculator for Children & Teens
Calculate BMI for children and teenagers aged 2–20 using CDC age-and-sex-specific percentile charts. Children's BMI is interpreted differently from adult BMI.
BMI = weight ÷ height²; classified by CDC percentile for age/sex
Metabolic Age Calculator
Calculate your metabolic age — how your BMR compares to the average for your age group. A lower metabolic age indicates a healthier, more efficient metabolism.
Metabolic age = age group whose avg BMR matches yours
Biological Age Calculator
Find out how old your body really is. Estimate your biological age from 12 lifestyle factors including exercise, sleep, stress, diet, and heart rate.
Levine PhenoAge Lifestyle Model
Comprehensive Health Monitoring Tools
Our health calculators provide a holistic view of your physical wellbeing. From understanding your weight status with BMI to ensuring adequate hydration and identifying your ideal weight range, these tools give you the data-driven insights to make informed health decisions.
Each calculator identifies the formula or reference standard it uses where applicable. Results are population-level estimates, not diagnosis or personalised medical advice.
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