Health & Body
Health & Fitness Calculators
Body metrics, calories burned, strength and pregnancy dates. Free calculators with formulas and worked examples.
Body measurements
BMI CalculatorCalculate your body mass index (BMI) from your height and weight, see which adult category it falls in, and find the weight…Body Fat CalculatorEstimate your body fat percentage from a tape measure, using the U.S. Navy circumference method. No calipers or scales needed.Ideal Weight CalculatorSee what four classic formulas suggest for your height.Healthy Weight Range CalculatorWhat weights fall in the normal BMI range for your height?Body Surface Area (BSA) CalculatorBSA is used to scale drug doses and cardiac output.Waist-to-Hip Ratio CalculatorMeasure your waist and hips to get your ratio.Waist-to-Height Ratio CalculatorKeep your waist to less than half your height.Lean Body Mass CalculatorHow much of your weight is not fat?Body Adiposity Index (BAI) CalculatorEnter your hip circumference and height to estimate body fat with BAI.A Body Shape Index (ABSI) CalculatorEnter waist, height and weight to calculate your body shape index.Ponderal Index Calculator (Rohrer's Index)Enter height and weight to get the ponderal index.Blood Volume Calculator (Nadler's Formula)Enter height, weight and sex.
Calories and energy
BMR CalculatorEstimate how many calories your body burns at rest (BMR), and how many you use in a day at your activity level, using the…Calorie Burn CalculatorEstimate how many calories you burn during exercise or daily activity from your body weight, the activity and how long you do it.Walking Calories Calculator (ACSM Equation)Enter your speed, incline, time and weight to estimate calories burned walking.Running Calories Calculator (ACSM Equation)Enter your speed, incline, time and weight to estimate calories burned running.
Strength training
Pregnancy
Heart rate and fitness
Running
Safety
Clinical
Creatinine Clearance Calculator (Cockcroft–Gault)An education tool that estimates kidney function. It cannot replace a clinician's assessment.eGFR Calculator (CKD-EPI 2021)An education tool that estimates kidney filtration. Results need clinical interpretation.Mean Arterial Pressure CalculatorConvert a blood pressure reading into MAP and pulse pressure.QTc Calculator (Corrected QT Interval)Enter the QT interval and heart rate to get the corrected QT with four formulas.Anion Gap Calculator (with Albumin Correction)Enter electrolyte values to calculate the anion gap.Corrected Calcium Calculator (for Albumin)Enter total calcium and albumin to get albumin-corrected calcium.Medication Dosage Calculator (mg/kg)Enter weight, the prescribed mg/kg and the liquid concentration to work out the volume.IV Drip Rate Calculator (Drops per Minute and mL/h)Enter the volume, infusion time and giving-set drop factor to get the drip rate.Ideal and Adjusted Body Weight Calculator (Devine)Enter height, sex and actual weight to get ideal and adjusted body weight.Glasgow Coma Scale (GCS) CalculatorChoose the best response in each category to get the GCS score.
Weight management
Diabetes
Heart health
Blood Pressure Category Calculator (AHA 2017)Enter your systolic and diastolic readings to see your blood pressure category.Cholesterol Ratio Calculator (with Friedewald LDL)Enter your lipid panel to see your cholesterol ratios and estimated LDL.CHA₂DS₂-VASc Score CalculatorTick the risk factors that apply to get the CHA₂DS₂-VASc score.
Lifestyle
Pregnancy and fertility
Ovulation Calculator (Fertile Window)Enter the first day of your last period and your cycle length to see your fertile days.Period Calculator (Next Period Dates)Enter your last period's start date and cycle length to predict the next ones.Conception Date CalculatorEnter your due date (or last period) to estimate when conception happened.IVF Due Date CalculatorEnter your transfer date and embryo age to get your IVF due date.Pregnancy Weight Gain Calculator (IOM Guidelines)Enter your pre-pregnancy height and weight to see the recommended weight gain.hCG Doubling Time CalculatorEnter the two hCG results and the hours between the tests.
Children
Body composition
Total Body Water Calculator (Watson Formula)Enter age, sex, height and weight to estimate how much water your body contains.FFMI Calculator (Fat-Free Mass Index)Enter your weight, height and body-fat percentage.Body Fat Percentage from BMI CalculatorA quick body-fat estimate when you only know height and weight.
Lab values
LDL Cholesterol Calculator (Friedewald Formula)Enter your lipid panel results and the unit.BUN to Creatinine Ratio CalculatorEnter BUN and creatinine from your blood test.Free Water Deficit Calculator (Hypernatremia)Enter the serum sodium, weight and patient group. For clinicians and students.Corrected Sodium Calculator (Hyperglycemia)Enter the measured sodium and blood glucose.
Energy and calories
Sleep
Fitness
About these calculators
Numbers can help you track fitness, but they are estimates, not diagnoses. These calculators cover body measurements, daily energy needs, exercise calories, strength estimates and pregnancy dates. For personal medical decisions, talk to a qualified professional.
Each calculator explains its formula, includes a worked example and lists its sources. Read how we check them on our editorial policy page, or browse all calculators.
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Please note: TheCalcTools gives general estimates for information and education. It is not financial, medical, legal or tax advice, and results should be checked before you make a decision. See our disclaimer and about page.