Health & fitness calculators
BMI, calories, body fat, heart rate, pregnancy and sleep.
- A1C CalculatorConvert an A1C (HbA1c) result to estimated average glucose (eAG) in mg/dL and mmol/L, or go the other way, and see the diagnostic range.
- Alcohol Units CalculatorCount UK alcohol units and US standard drinks in what you drink, and compare a week’s drinking with the 14-unit guideline.
- Anion Gap CalculatorCalculate the serum anion gap from sodium, chloride and bicarbonate, with an optional correction for low albumin.
- Army Body Fat CalculatorUS Army body fat percentage formula.
- BAC CalculatorBlood alcohol content estimate.
- Blood Sugar ConverterConvert blood glucose readings between mg/dL (used in the US) and mmol/L (used in the UK, Canada and most of the world).
- BMI CalculatorBody mass index from height and weight. Uses metric (kg, cm) or imperial (lb, ft/in) and shows category: underweight, normal, overweight, obese.
- BMR / Calorie CalculatorBasal metabolic rate and daily calories at rest. Choose Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle; add activity level for TDEE.
- Body Fat Percentage CalculatorEstimate body fat % with the U.S. Navy method. Enter sex, height, weight, and circumferences (waist, neck; hip for females) in cm.
- Body Roundness Index CalculatorCalculate your body roundness index (BRI) from waist and height, a newer alternative to BMI that better reflects belly fat.
- Body Surface Area CalculatorBSA (Mosteller formula).
- Body Type CalculatorBody shape/somatotype (simplified).
- Caffeine CalculatorEstimate how much caffeine is still in your system hours after a coffee or energy drink, using caffeine’s roughly five-hour half-life.
- Calories Burned CalculatorEstimate calories burned in a single session by activity type and duration. Uses MET (metabolic equivalent); enter weight, minutes, and activity (walk, run, bike, etc.).
- Carbohydrate CalculatorDaily carb needs.
- Child Height PredictorEstimate how tall a child will be as an adult from the parents’ heights, using the mid-parental height method, with the usual range.
- Chipotle Calorie CalculatorAdd up calories for Chipotle or any meal items.
- Cholesterol Ratio CalculatorCalculate your total cholesterol to HDL ratio, non-HDL cholesterol and triglyceride to HDL ratio from a lipid panel.
- Conception CalculatorConception date from due date.
- Corrected Calcium CalculatorCorrect a total serum calcium level for low or high albumin with the Payne formula.
- Creatinine Clearance CalculatorEstimate creatinine clearance with the Cockcroft-Gault equation from age, weight, sex and serum creatinine, as used for drug dosing.
- Dog Chocolate Toxicity CalculatorEstimate how dangerous the chocolate your dog ate is, from the dog’s weight, the type of chocolate and how much.
- Dosage CalculatorCalculate a weight-based medication dose in mg and the liquid volume in mL from the dose per kilogram and the concentration.
- DOTS CalculatorCalculate your powerlifting DOTS score from your total and body weight, to compare lifters across weight classes.
- Fat Intake CalculatorDaily fat intake (grams/calories).
- FFMI CalculatorCalculate your fat-free mass index (FFMI) from height, weight and body fat, a muscularity measure that’s more useful than BMI for lifters.
- GFR CalculatorEstimated kidney function (eGFR).
- Ideal Weight CalculatorIdeal body weight by height and frame.
- IV Drip Rate CalculatorCalculate an IV infusion rate in drops per minute (gtt/min) and mL per hour from the volume, time and tubing drop factor.
- Lean Body Mass CalculatorLean body mass from weight and body fat.
- Macro CalculatorSplit your daily calories into grams of protein, carbs and fat for a balanced, high-protein, low-carb or keto diet.
- Mean Arterial Pressure CalculatorCalculate mean arterial pressure (MAP) and pulse pressure from a blood pressure reading, and see which blood pressure category it falls in.
- One Rep Max Calculator1RM strength estimate.
- Overweight CalculatorHow much over ideal weight (BMI-based).
- Ovulation CalculatorEstimated ovulation and fertile window.
- Pace CalculatorRunning pace (min/mile or min/km).
- Pack Years CalculatorCalculate your smoking history in pack-years, the measure doctors use to decide on lung cancer screening.
- Period CalculatorNext period and cycle length.
- Pet Calorie CalculatorEstimate how many calories your dog or cat needs per day from its weight and life stage, using the veterinary RER formula.
- Pregnancy Due Date CalculatorDue date from last period or conception.
- Pregnancy Weight Gain CalculatorRecommended pregnancy weight gain.
- Protein CalculatorDaily protein needs.
- QTc CalculatorCorrect the QT interval for heart rate with the Bazett, Fridericia, Framingham and Hodges formulas.
- Race Time PredictorPredict your finish time for a 5K, 10K, half marathon or marathon from a recent race, using the Riegel formula, with the pace you’d need.
- Sleep CalculatorWake times for full sleep cycles.
- Steps to Miles CalculatorConvert steps to miles and kilometers using your height to estimate stride length, plus roughly how many calories the walk burned.
- Target Heart Rate CalculatorTarget zones by age and intensity.
- TDEE / Macros CalculatorTotal daily energy expenditure and target calories for maintain, lose, or gain. Includes zigzag option and suggested protein, carbs, and fat.
- VO2 Max CalculatorEstimate VO2 max from resting heart rate (Uth) or Cooper test.
- Waist-to-Height Ratio CalculatorCalculate your waist-to-height ratio, a simple measure of belly fat linked to heart and metabolic risk. Keep your waist under half your height.
- Waist-to-Hip Ratio CalculatorWaist-to-hip ratio and health risk category.
- Water Intake CalculatorRecommended daily water intake by weight and activity level. Simple guideline in liters (and cups); adjust for thirst and climate.
- Watts per Kilogram CalculatorCalculate your cycling power-to-weight ratio (W/kg) from FTP and body weight, and see roughly where it ranks.
- Weight Loss CalculatorEstimate how long it will take to reach your goal weight at a daily calorie deficit, and how much you’d lose each week.
- Weight Loss Percentage CalculatorCalculate the percentage of body weight you’ve lost (or gained) between a starting and current weight.
- Weight Watchers Points CalculatorWW Points (simplified).
These tools estimate calories, body composition, hydration, and other health-related numbers. They use standard formulas (BMR, TDEE, MET, Navy body fat) and are intended for general awareness and planning—not as a substitute for medical or dietary advice.
Who they're for: People tracking diet or activity, athletes setting calorie or macro targets, and anyone curious about BMI, water intake, or calories burned in a workout. Inputs are simple (weight, height, age, activity level) and results are clearly labeled as estimates.
Common use cases: Estimating BMR and daily calories (TDEE), setting a target intake for weight loss or gain, estimating calories burned in a single session (e.g. run or gym), getting a body fat estimate from measurements, and checking recommended water intake. For medical conditions or personalized plans, consult a doctor or dietitian.