Free Health and Medical Calculators

Choose from over 100 free health and medical calculators for pregnancy, baby and child growth, period and ovulation tracking, nutrition, fitness, weight, kidney function, A1C and medication supply. Enter a few details and get an instant result with an animated gauge, scale, calendar and charts. Everything runs in your browser, so nothing you type is stored or sent anywhere.

Weight & BMI

• Body Mass Index (BMI) Calculator - Weight-to-height index with WHO and Asian cut-offs.
• Ideal Weight Calculator - Devine, Robinson, Miller and Hamwi formulas compared.
• Healthy Weight Range Calculator - Your lowest and highest healthy weight for your height.
• BMI Prime Calculator - BMI as a ratio of the upper healthy limit.
• Ponderal Index Calculator - Weight over height cubed, better for tall or short people.

Body composition

• Body Fat Percentage Calculator - US Navy tape method with fat mass and lean mass.
• Lean Body Mass Calculator - Boer, James and Hume estimates of lean mass.
• Body Surface Area (BSA) Calculator - Mosteller, DuBois, Haycock and Gehan-George formulas.
• Relative Fat Mass (RFM) Calculator - Body fat estimate from height and waist only.
• Army Body Fat Calculator - Tape test with age-based pass/fail standards.
• FFMI Calculator - Fat-free mass index and muscle potential.

Body measurements

• Waist-to-Height Ratio Calculator - Keep your waist under half your height.
• Waist-to-Hip Ratio Calculator - Fat distribution and WHO abdominal obesity check.
• Waist Circumference Risk Assessment - Check your waist size against WHO and South Asian limits.

Energy & nutrition

• Basal Metabolic Rate (BMR) Calculator - Calories your body burns at complete rest.
• Total Daily Energy Expenditure (TDEE) - Calories you burn per day including activity.
• Daily Calorie Needs Calculator - Calorie targets for loss, maintenance or gain, with macros.

Weight management

• Weight Loss Calculator - How long to reach your goal weight, with a weekly projection.
• Weight Gain Calculator - Calories and weeks needed to reach a higher goal weight.
• Calorie Deficit Calculator - Daily calories to eat and fat loss from your deficit.
• Calorie Surplus Calculator - Daily calories to eat to build weight and muscle.

Nutrition & hydration

• Macronutrient Calculator - Protein, carb and fat grams for your calories and diet style.
• Daily Water Intake Estimator - Quick litres-per-day estimate from weight, activity and climate.
• Protein Intake Calculator - Daily protein range for your body weight and goal.
• Carbohydrate Intake Calculator - Daily carbohydrate grams for your calories and eating style.
• Fat Intake Calculator - Daily fat grams and a healthy saturated, mono and poly mix.
• Fiber Intake Calculator - Daily fibre target by age and sex.
• Sugar Intake Limit Calculator - Your daily free-sugar limit in grams and teaspoons.
• Sodium Intake Calculator - Daily sodium and salt limit by age and health.
• Daily Water Intake Calculator - Detailed water goal with exercise, climate and pregnancy.
• Meal Calorie Calculator - Add foods and grams to total a meal’s calories and macros.
• Recipe Nutrition Calculator - Nutrition per serving for any home recipe.

Exercise & calories

• Calories Burned Calculator - Calories burned by 30 activities using MET values.
• Walking Calories Calculator - Calories burned walking by speed, time or distance.
• Running Calories Calculator - Calories burned running from distance and time.
• Cycling Calories Calculator - Calories burned cycling from distance and time.
• Steps-to-Distance Calculator - Convert steps to kilometres or miles using your stride.
• Steps-to-Calories Calculator - Calories burned from your daily step count.

Fitness & training

• Target Heart Rate Calculator - Max heart rate and 5 training zones by age.
• Heart Rate Reserve Calculator - Karvonen zones from your resting heart rate.
• One-Rep Max Calculator - 1RM from reps with 7 formulas and training zones.
• Workout Volume Calculator - Total sets, reps and tonnage for a training session.
• Pace Calculator - Running pace, finish time or distance in one tool.
• Running Speed Calculator - Speed in km/h, mph and m/s with a fitness gauge.
• Race Finish-Time Predictor - Predict 10K, half and marathon times from a recent race.
• VO₂ Max Estimator - Estimate VO2 max from a run, walk or resting heart rate.

Sleep & recovery

• Sleep Duration Calculator - Best bedtime or wake-up time using 90-minute cycles.

Period & fertility

• Period Tracker and Next Period Calculator - Predict your next 3 periods and see your cycle phase.
• Ovulation Calculator - Find your ovulation day, fertile days and peak fertility.
• Fertile Window Calculator - Your fertile days and chance of pregnancy today.
• Pregnancy Test Date Calculator - The best day to take a pregnancy test.
• Next Ovulation Date Estimator - Predict your next 3 ovulation dates with a margin.
• Conception Date Estimator - Estimate when you conceived and your due date.
• Implantation Window Estimator - When implantation happens and when spotting may occur.
• Missed Period Calculator - How late is your period and what to do next.
• Menstrual Calendar - A calendar of your periods, fertile days and PMS days.
• Menstrual Cycle Length Calculator - Your average, shortest and longest cycle from past periods.
• Period Duration Calculator - How many days your periods last, with a trend chart.
• Irregular Period Tracker - Predict a window for your next period when cycles vary.
• PMS Symptom Tracker - Score your PMS symptoms and see which are strongest.
• Pregnancy Planning Age Calculator - How age affects your chance of conceiving.

Pregnancy

• Pregnancy Due Date Calculator - Your estimated due date from LMP, conception or ultrasound.
• Pregnancy Week Calculator - How many weeks pregnant you are, with baby size and growth charts.
• Pregnancy Trimester Calculator - Your trimester, its start and end dates, and days left.
• Pregnancy Month Calculator - Convert weeks pregnant into months of pregnancy.
• IVF Pregnancy Due Date Calculator - Due date from your embryo transfer date and embryo age.
• Pregnancy Test Timing Calculator - When your test can detect hCG, by test sensitivity.
• Pregnancy Weight Gain Guide - Recommended weight gain by week for your starting BMI.
• Pregnancy BMI Calculator - Your pre-pregnancy BMI and the weight gain it suggests.
• Pregnancy Calorie Needs Estimator - How many calories you need in each trimester.
• Pregnancy Hydration Guide - Daily water goal for pregnancy and breastfeeding.
• Pregnancy Appointment Timeline - Your antenatal visits, scans and tests with dates.
• Fetal Movement Log - Count to 10 kicks and see how long it takes.
• Contraction Timer - Time contractions and see when to go to the hospital.
• Contraction Interval Calculator - Is it time to go? Enter your interval, length and travel time.
• Miscarriage Recovery Information Guide - What to expect physically after a miscarriage.

Postpartum & newborn

• Postpartum Recovery Timeline - Week-by-week recovery after vaginal or caesarean birth.
• Breastfeeding Session Tracker - Log feeds, sides and times with charts.
• Breast Milk Storage Time Guide - How long breast milk keeps at room temperature, fridge and freezer.
• Baby Feeding Amount Estimator - How much milk per feed and per day for your baby.
• Newborn Feeding Interval Tracker - Track feed times and the gaps between them.
• Baby Sleep Duration Tracker - Total sleep, naps and nights against recommended hours.
• Baby Temperature Guide - Is it a fever? Normal baby temperature by method.
• Baby Age Calculator - Your baby’s exact age in months, weeks and days.
• Infant Age in Weeks Calculator - Baby’s age in weeks and days, with week-by-week events.
• Corrected Age for Premature Babies - Age adjusted for prematurity, for milestones and growth.

Child growth

• Weight-for-Age Calculator - Child weight percentile and z-score from 0 to 19 years.
• Height-for-Age Calculator - Child height percentile and stunting check.
• Growth Percentile Calculator - Weight, height and BMI percentiles in one growth chart.
• Baby Growth Percentile Calculator - Weight, length and BMI percentiles from birth to 2 years.
• Pediatric BMI Percentile Calculator - BMI-for-age percentile and weight category for ages 2-19.
• Child Height Predictor - Predict adult height from parents’ heights and growth so far.

Contraception & sexual health

• Safe Period / Safe-Sex Day Estimator - Lower-risk and high-risk days, with honest limits.
• Pregnancy Risk Information Tool - Estimate pregnancy risk from a single act, by cycle day and method.
• Emergency Contraception Time Window Calculator - How many hours you have left for each emergency option.
• Condom Size Guide - Find the right condom width for a better, safer fit.
• Contraception Comparison Tool - Compare 14 birth control methods against your priorities.
• Birth Control Pill Reminder Schedule - Your pill calendar with active and break days.
• STI Testing Date Guide - When to test for chlamydia, HIV, syphilis and more.
• Breastfeeding and Fertility Eligibility Checker - Check if breastfeeding can work as contraception (LAM).

Women's health checks

• Menopause Age / Stage Information Tool - Your likely menopause stage and what to expect.
• Anemia Risk Screening Tool for Women - Screen your risk of iron-deficiency anaemia.
• PCOS Symptom Assessment Tool - Check if your symptoms fit a PCOS pattern.
• Endometriosis Symptom Assessment Tool - See whether your pain pattern fits endometriosis.

Medication & lab results

• eGFR Calculator (CKD-EPI 2021) - Kidney function from creatinine, age and sex with CKD stage.
• Creatinine Clearance Calculator (Cockcroft-Gault) - Cockcroft-Gault CrCl for kidney drug dosing, with ideal body weight.
• A1C to Average Glucose Calculator - Convert HbA1c to estimated average glucose (mg/dL, mmol/L) and back.
• Drug Half-Life Calculator - How much of a medicine is left in your body after a number of hours.
• Medication Days Supply and Refill Date Calculator - How long a prescription lasts and the date to order a refill.
• Medicine Treatment Cost Comparator - Total cost, cost per day and generic savings for a prescribed treatment, with live pharmacy prices.

Home energy

• Appliance Electricity Cost & Solar Payback Calculator - Monthly kWh and bill for ACs, fans, fridges and pumps, plus solar size and payback.

Education

• CGPA Recovery Calculator - The GPA you need in remaining credits to reach your target CGPA.

These calculators are for education only and are not medical advice. See the medical disclaimer and how we build and review our tools. Looking for medicine prices? Compare medicine prices in 32 countries on MediHub.