Health Calculators
30 calculators
Body metrics and reference ranges: BMI, blood pressure categories, HbA1c conversion, calorie and alcohol estimates, and growth percentiles. The thresholds quoted come from widely published public-health tables, and different bodies draw the lines in slightly different places. These numbers describe a population, not a diagnosis — anything that affects treatment belongs with a clinician who knows your history.
- A1C Calculator Convert an HbA1c percentage into estimated average glucose in both mg/dL and mmol/L.
- Alcohol Calorie Calculator Calculate the calories in a drink from its volume and ABV, based on the 7 calories per gram of pure alcohol.
- Baby Growth Reference Calculator Compare an infant’s weight and length with WHO median reference values for age and sex, from birth to 24 months.
- Blood Alcohol Calculator Estimate blood alcohol concentration from your weight, sex, number of drinks and hours elapsed.
- Blood Pressure Calculator Calculate estimated mean arterial pressure and pulse pressure from systolic and diastolic readings.
- BMI Calculator — Body Mass Index Free BMI calculator. Enter your weight and height to get your Body Mass Index and health category instantly.
- BMR Calculator — Basal Metabolic Rate Calculate your Basal Metabolic Rate (BMR) with the Mifflin-St Jeor equation. See how many calories your body burns at rest.
- Body Fat Calculator Estimate body fat percentage from tape measurements using the US Navy circumference method.
- Body Surface Area Calculator Estimate body surface area in m² from height and weight. Compare Mosteller, Du Bois and Haycock formulas using metric or imperial inputs.
- Calorie Calculator Calculate your basal metabolic rate and the daily calories you need to maintain your current weight.
- Calorie Deficit Calculator Work out the daily calorie target needed to reach a goal weight by a chosen date.
- Cat Age Calculator Convert your cat’s age into human years and see the life stage they are in.
- Dog Age Calculator Estimate a dog’s human-age equivalent using a general rule of thumb.
- Heart Rate Zone Calculator Calculate your maximum heart rate and personalised training zones using the Karvonen method.
- Ideal Weight Calculator Compare ideal body weight estimates from four standard clinical formulas.
- Lean Body Mass Calculator Estimate lean body mass and fat mass using the Boer formula.
- Macro Calculator Split your daily calories into grams of protein, carbohydrate and fat.
- One Rep Max Calculator Estimate your one repetition maximum from a set you have already completed, using three standard formulas.
- Ovulation Calculator Predict your ovulation date, fertile window and next period from your last period and cycle length.
- Pregnancy Due Date Calculator Estimate your due date from the first day of your last period using Naegele’s rule.
- Pregnancy Weight Gain Calculator See the recommended total weight gain range for your pre-pregnancy BMI.
- Protein Intake Calculator Calculate how many grams of protein you need each day based on your weight and goal.
- Running Calories Calculator Estimate the calories burned on a run from your weight, distance and time.
- Sleep Calculator Find the best times to go to sleep based on 90-minute sleep cycles and your wake-up time.
- Steps to Miles Calculator Convert a step count into distance and estimated calories using your height.
- TDEE Calculator — Total Daily Energy Expenditure Estimate daily energy expenditure from an equation-based BMR and selected activity factor.
- Cooper 12-Minute Run VO₂ Estimate Estimate VO₂ max from distance covered during a 12-minute Cooper run test.
- Waist-to-Hip Ratio Calculator Calculate waist circumference divided by hip circumference; the result is a ratio only.
- Walking Calories Calculator Estimate how many calories you burn walking, based on your weight, time and speed.
- Water Intake Formula Calculator Explore a simplified water-intake formula; the result is not an individualized hydration recommendation.
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Adult screening tools such as BMI use published cut-points and say what they are not measuring. Energy and body-size calculators list units and age limits in the method note — read those before treating a number as advice.
Work from the measurements you have
BMI uses height and weight, while body-fat estimates require additional measurements. Body surface area offers several named equations; comparing their outputs is a model comparison, not a way to select a treatment or dose.
Distinguish estimates from recorded activity
BMR and TDEE estimate different energy quantities. Pace calculators instead relate distance and time; a calorie estimate adds further assumptions about the activity and person. Use the tool that matches the available measurements.
Read the result in context
Check whether a model’s population and measurement assumptions fit the task. These calculations do not diagnose a condition or replace individualized medical assessment. A change in an estimate can come from changed inputs or a different equation, rather than a change in health.