Ctrl K
Health Calculators

Health Calculators

Explore adult health and fitness estimates with clear inputs, explanations and the context needed to interpret each result.

Age CalculatorUse this health-focused calculator for quick estimates and planning.BMI CalculatorUse this health-focused calculator for quick estimates and planning.BMR Calculator for WomenUse this health-focused calculator for quick estimates and planning.BMR CalculatorUse this health-focused calculator for quick estimates and planning.Body Fat CalculatorUse this health-focused calculator for quick estimates and planning.Calories CalculatorUse this health-focused calculator for quick estimates and planning.Due Date CalculatorUse this health-focused calculator for quick estimates and planning.Fasting Calories Burning CalculatorUse this health-focused calculator for quick estimates and planning.Ideal Weight CalculatorUse this health-focused calculator for quick estimates and planning.Pace CalculatorUse this health-focused calculator for quick estimates and planning.Pregnancy CalculatorUse this health-focused calculator for quick estimates and planning.Pregnancy Conception CalculatorUse this health-focused calculator for quick estimates and planning.Ladies Period Predictor CalculatorUse this health-focused calculator for quick estimates and planning.Marathon Pace CalculatorUse this health-focused calculator for quick estimates and planning.Pregnancy Weight Gain CalculatorEstimate recommended pregnancy weight-gain ranges from pre-pregnancy BMI for a singleton or twin pregnancy and compare current gain.Height Predictor CalculatorEstimate a child’s adult height from parental heights using the mid-parental-height method, with metric and imperial results.Bra Size CalculatorEstimate a starting bra band and cup size from snug underbust and full-bust measurements for US or UK sizing.Army Body Fat / WHtR CalculatorCalculate the current U.S. Army waist-to-height ratio body-composition screening value and compare it with the 0.55 benchmark.Carbohydrate CalculatorConvert daily calories and a chosen carbohydrate percentage into grams of carbohydrate per day and per meal.Lean Body Mass CalculatorEstimate lean body mass with Boer, James and Hume formulas using height, weight and sex, with metric and imperial support.One Rep Max CalculatorEstimate one-repetition maximum strength from a lifted weight and repetition count using Epley, Brzycki and Lombardi formulas.Fat Intake CalculatorConvert daily calories and chosen total-fat and saturated-fat percentages into grams per day.Ovulation CalculatorEstimate an ovulation date, fertile window and next expected period from the first day of the last menstrual period and average cycle length.GFR Calculator (2021 CKD-EPI)Estimate adult eGFR from age, sex and serum creatinine using the race-free 2021 CKD-EPI creatinine equation.Body Type CalculatorEstimate a body-shape category from shoulder, bust, waist and hip measurements and review the proportion ratios used.Body Surface Area CalculatorEstimate body surface area with Mosteller, Du Bois, Haycock and Gehan-George formulas using height and weight.BAC CalculatorEstimate blood alcohol concentration from body weight, standard drinks and time using a simplified Widmark model, with a strong driving-safety warning.

Uses of Health Category Calculators

Health category calculators are tools that can be used to perform a wide range of health-related calculations, including:

Body mass index (BMI): A calculator that determines an individual's BMI can help determine if they are at a healthy weight for their height.

Target heart rate: A calculator that determines an individual's target heart rate can help them determine how hard they need to work during a cardio workout to reach their fitness goals.

Calorie needs: A calculator that determines an individual's calorie needs can help them determine how many calories they should be consuming each day to maintain, gain, or lose weight.

Basal metabolic rate (BMR): A calculator that determines an individual's BMR can help them understand how many calories their body burns at rest, which can be useful for weight loss or maintenance.

Ideal weight: A calculator that determines an individual's ideal weight can help them determine what their ideal weight range should be based on their height and body frame size.

Nutrient needs: A calculator that determines an individual's nutrient needs can help them ensure that they are getting enough of essential nutrients such as protein, carbohydrates, and fats.

Pregnancy: There are several types of health category calculators that can be used during pregnancy, including calculators that determine the due date, the size of the fetus, and the probability of conceiving.

Other: There are many other types of health category calculators that can be used for a wide range of purposes, including calculating the risk of developing certain health conditions, determining the dosage of medication, and estimating the likelihood of developing a disease based on genetic risk factors.

Trending & Newly Added Calculators

Added or improved from the supplied Google Trends search data, with transparent formulas and editable assumptions where rates can change.

Calorie Deficit CalculatorTDEE and adjustable calorie target.Maintenance Calories CalculatorCorrected Mifflin–St Jeor TDEE estimate.

More calculators

Macro CalculatorEstimate BMR, TDEE, calorie target and daily protein, carbohydrate and fat grams using Mifflin–St Jeor and configurable macro settings.Calories Burned CalculatorEstimate calories burned from body weight, activity MET value and duration, with kcal per hour and kilojoules.Target Heart Rate CalculatorCalculate a target heart-rate zone using Karvonen heart-rate reserve or percent of estimated maximum, with two max-HR formulas.Protein CalculatorCalculate daily protein grams from body weight and an editable grams-per-kilogram target, with per-meal distribution and calorie contribution. No account or upload required.

New Calculators

Sleep CalculatorNew calculator

Water Calculator

Water CalculatorCalculate tank water in litres, daily intake estimates and water unit conversions.

Understand what a health estimate represents

Choose a calculator that matches the quantity you are checking, such as BMI, a calorie estimate or a date-based estimate. Read the tool's population and input requirements before comparing results. An adult screening formula and a child or teen growth assessment are not interchangeable.

Units and input quality

Confirm whether height is requested in centimeters or feet and inches, and whether weight is entered in kilograms or pounds. Use the metric or US selector for that conversion instead of typing a number from one system into a field labeled for the other. An input-unit error can create a large numerical difference.

BMI in context

The BMI calculator relates height and weight and displays an adult category. The CDC's adult BMI resource explains that BMI is one health indicator considered with other information. The result alone does not describe a person's full health situation or establish a diagnosis.

For repeated checks, use consistent measurements and review the explanation below the chosen tool. Treat estimated calorie needs or dates as estimates within the stated model. When interpreting a health concern or making a treatment decision, discuss the relevant measurements and circumstances with a healthcare professional.