Health
Health Calculators
Use transparent screening estimates with clearly stated methods and limitations.
63 tools
Body & BMI 7
Body Surface Area Calculator
Body surface area calculator: Mosteller formula from height and weight.
Frame Size Calculator
Frame size calculator: small, medium, or large body frame from wrist.
Lean Body Mass Calculator
Lean body mass calculator: LBM from weight and height (Boer).
Waist Hip Ratio Calculator
Waist to hip ratio calculator: WHR and health risk category.
Waist to Height Ratio Calculator
Waist-to-height ratio calculator: assess abdominal obesity risk from waist and height.
BMI Calculator
Calculate BMI quickly and privately in your browser.
Body Fat Estimate Calculator
Estimate adult body-fat percentage with the U.S. Navy circumference method and clear limitations.
Fitness & Calories 17
Calorie Deficit Calculator
Calorie deficit calculator: weight-loss timeline from daily deficit and target pounds.
Calorie Target Calculator
Calorie target calculator: maintenance, deficit, and surplus targets from weight, height, age, and activity.
Cycling Calories Calculator
Cycling calories calculator: calories burned cycling by weight and time.
Gym Cost Per Visit Calculator
Gym cost per visit calculator: is your membership actually worth it?
Heart Rate Recovery Calculator
Heart rate recovery calculator: HR drop after exercise.
Heart Rate Zones Calculator
Heart rate zones calculator: target training zones from age and resting heart rate, computed locally.
Macro Split Calculator
Macro split calculator: carbs from calories, protein, and fat targets.
Maintenance Calories Calculator
Maintenance calories calculator: calories to hold your weight (Mifflin-St Jeor).
Steps to Miles Calculator
Steps to miles calculator: distance walked and calories burned from step count.
Stride Length Calculator
Stride length calculator: stride from height for walking or running.
Swimming Calories Calculator
Swimming calories calculator: calories burned swimming by weight and time.
VO2 Max Calculator
VO2 max calculator: estimate aerobic fitness from a 12-minute run or resting heart rate.
VO2 Max Calculator
VO2 max calculator: estimate from a 12-minute Cooper test.
Walking Calories Calculator
Walking calories calculator: calories burned walking by weight and time.
Calorie Calculator
Estimate daily calories and macros from simple inputs.
Macro Planning Calculator
Allocate a user-selected adult calorie total across configurable protein, fat, and carbohydrate assumptions.
Pace Calculator
Calculate your running pace per km or mile from distance and time, plus speed and predicted race times.
Nutrition & Hydration 9
Blood Sugar Converter
Blood sugar converter: convert glucose between mg/dL and mmol/L instantly.
Caffeine Half-Life Calculator
Caffeine half-life calculator: how much caffeine remains in your system over time.
Daily Water Intake Calculator
Daily water intake calculator: estimate hydration needs from body weight and activity.
Fasting Window Calculator
Fasting window calculator: eating window from fast start and length.
Intermittent Fasting Calculator
Intermittent fasting calculator: convert between eating windows and fasting hours.
Protein Shake Calculator
Protein shake calculator: protein per shake from scoops.
Sodium Calculator
Sodium calculator: mg sodium to salt grams and daily value.
Sugar in Drinks Calculator
Sugar in drinks calculator: teaspoons and daily value from grams.
Weight Loss Timeline Calculator
Weight loss timeline calculator: how long a healthy weekly deficit will take.
Sleep & Recovery 4
Sleep Cycle Calculator
Sleep cycle calculator: find ideal bedtimes that end on a 90-minute sleep cycle for your wake time.
Sleep Cycle Calculator
Sleep cycle calculator: best bedtime to wake refreshed in 90-minute cycles.
Sleep Debt Calculator
Sleep debt calculator: accumulated lost sleep from target hours, actual hours, and days tracked.
Sleep Length Calculator
Sleep length calculator: hours and minutes from sleep cycles, plus when to wake.
Women's Health 8
Baby Formula Calculator
Baby formula calculator: ounces per feeding from baby weight.
Bra Size Calculator
Bra size calculator: band and cup size from underbust and bust measurements.
Conception Calculator
Conception calculator: conception date and fertility window from due date.
Menstrual Cycle Calculator
Menstrual cycle calculator: next period and estimated fertile window (private, nothing stored).
Period Cycle Calculator
Period cycle calculator: estimate the next period and fertile window from cycle length.
Pregnancy Due Date Calculator
Pregnancy due date calculator: estimate the due date from the first day of the last menstrual period.
Pregnancy Weight Gain Calculator
Pregnancy weight gain calculator: IOM recommended ranges by BMI and week.
Pregnancy Calculator
Estimate your pregnancy due date and current week from your last period, conception date, or a known due date. Private, no account.
Blood & Heart 6
Blood Alcohol Content Calculator
Blood alcohol content (BAC) calculator: Widmark estimate from drinks, weight, and time \u2014 informational only.
Blood Pressure Category Calculator
Blood pressure category calculator: classify a systolic/diastolic reading using the AHA categories.
Cholesterol Ratio Calculator
Cholesterol ratio calculator: total-to-HDL and LDL-to-HDL ratios from a lipid panel.
GFR Calculator
eGFR calculator (CKD-EPI 2021): estimated kidney filtration rate from creatinine, age, and sex.
Metabolic Age Calculator
Metabolic age calculator: how your BMR compares to your age group.
Pulse Pressure Calculator
Pulse pressure calculator: the gap between systolic and diastolic.
More health tools 12
A1c Calculator
A1c calculator: estimated average glucose from HbA1c.
Fetal Weight Calculator
Fetal weight calculator: estimated baby weight from ultrasound (Hadlock).
Gestational Age Calculator
Gestational age calculator: weeks pregnant and due date from last period.
Mean Arterial Pressure Calculator
Mean arterial pressure calculator: MAP from systolic and diastolic.
Medicine Dosage Calculator
Medicine dosage calculator: dose from body weight and mg/kg dosing instructions.
Pollen Forecast Calculator
Pollen forecast calculator: current pollen levels for any city.
Sensitivity Specificity Calculator
Sensitivity and specificity calculator: diagnostic test performance.
Sunscreen SPF Calculator
Sunscreen SPF calculator: burn protection time and reapplication.
UV Exposure Calculator
UV exposure calculator: minutes until sunburn by UV index and Fitzpatrick skin type.
Vitamin D Calculator
Vitamin D calculator: IU to mcg conversion with daily reference.
BMR & TDEE Calculator
Estimate adult BMR and TDEE from the Mifflin-St Jeor equation and an explicit activity multiplier.
Ideal Weight Calculator
Estimate your ideal body weight using seven common formulas (Hamwi, Devine, Robinson, Miller, Broca, Lorentz, Peterson) plus a healthy BMI range.