Explore 68 free tools for body composition, nutrition, fitness performance, pregnancy planning, and everyday health estimates. Each calculator works directly in your browser with no registration.
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BMI CalculatorEstimate body mass index from height and weight.BMI Prime CalculatorCompare BMI with the upper healthy-range reference.Body Fat CalculatorEstimate body-fat percentage using common measurement methods.Body Adiposity Index CalculatorEstimate adiposity from hip circumference and height.Ideal Weight CalculatorCompare several reference formulas for adult weight.Healthy Weight CalculatorEstimate an adult healthy-weight range and compare reference formulas.Adjusted Body Weight CalculatorEstimate adjusted weight for selected clinical calculations.Lean Body Mass CalculatorEstimate body weight excluding estimated fat mass.Waist-to-Hip Ratio CalculatorCalculate waist-to-hip ratio and review context.Waist-to-Height Ratio CalculatorCompare waist circumference with height.A Body Shape Index (ABSI) CalculatorCalculate ABSI from waist, BMI, height, and weight.Body Roundness Index CalculatorEstimate body roundness using waist and height.Relative Fat Mass CalculatorEstimate relative fat mass from waist and height.Ponderal Index CalculatorAssess weight relative to height cubed.Body Surface Area CalculatorEstimate body surface area with multiple formulas.Navy Body Composition CalculatorEstimate body fat using circumference measurements.Army Body Composition CalculatorEstimate body-fat percentage using Army-style measurements.Body Type CalculatorExplore common body-shape categories from your measurements.Body Frame Size CalculatorEstimate body frame size using wrist and height measurements.Fat-Free Mass Index (FFMI) CalculatorCompare lean mass relative to height.Skinfold Body Fat CalculatorEstimate body fat from skinfold measurements.Weight Loss Percentage CalculatorCalculate the percentage of body weight lost.Child and Teen BMI CalculatorCalculate BMI for children and teenagers with age context.
Nutrition & energy
BMR CalculatorEstimate calories used by the body at rest.Calorie CalculatorEstimate daily calories for maintenance or weight goals.TDEE CalculatorEstimate total daily energy expenditure by activity level.Macro CalculatorPlan daily protein, carbohydrate, and fat targets.Protein Intake CalculatorEstimate a daily protein target by goal and activity.Carbohydrate Intake CalculatorPlan a daily carbohydrate range.Fat Intake CalculatorEstimate a practical daily dietary-fat range.Fiber Intake CalculatorEstimate a daily fiber target and food planning range.Water Intake CalculatorEstimate daily fluid needs with activity adjustments.Calories Burned CalculatorEstimate activity energy use by duration and intensity.Calorie Deficit CalculatorEstimate a daily calorie target for gradual weight loss.Maintenance Calorie CalculatorEstimate calories needed to maintain current weight.Resting Metabolic Rate (RMR) CalculatorEstimate resting energy expenditure.Weight Loss CalculatorPlan calories and time for a weight-loss goal.Weight Gain Planner CalculatorPlan a calorie surplus and weight-gain timeline.Carb CalculatorEstimate daily carbohydrate needs by goal and activity.Protein CalculatorEstimate daily protein needs by weight and training goal.
Fitness & performance
Pace CalculatorConvert distance and time into pace and speed.Target Heart Rate CalculatorEstimate training zones with multiple methods.One-Rep Max CalculatorEstimate maximum strength from submaximal lifts.VO2 Max CalculatorEstimate aerobic fitness from field-test results.TDEE Calculator for AthletesEstimate energy needs with athlete training volume.Steps to Distance CalculatorConvert a step count into kilometers and miles.METs CalculatorEstimate activity calories from MET intensity.Running Cadence CalculatorCalculate running steps per minute.
Sleep & recovery
Pregnancy & reproductive health
Pregnancy CalculatorEstimate pregnancy dates and timeline milestones.Pregnancy Conception CalculatorEstimate conception timing from several date methods.Pregnancy Due Date CalculatorEstimate due date, trimester, and milestones.Pregnancy Weight Gain CalculatorCompare weight gain with general pregnancy ranges.Ovulation CalculatorEstimate ovulation and a possible fertile window.Period CalculatorForecast upcoming period dates from cycle history.Pregnancy Test CalculatorEstimate useful pregnancy-testing dates.hCG Doubling Time CalculatorCompare two quantitative hCG results over time.Conception Probability CalculatorReview a broad estimate based on timing and age group.
Health markers
Health conversions
More health & fitness tools
Sweat Rate CalculatorEstimate hourly fluid loss during exercise.Heart Rate Recovery CalculatorMeasure the drop in heart rate after exercise.Waist Circumference Risk CalculatorCompare waist size with common health-risk reference levels.Running Split CalculatorCalculate target split times for a running distance.Pregnancy Weeks to Months ConverterConvert pregnancy weeks and days to an approximate month and trimester.
How to use these calculators
- Choose the calculator that matches your question.
- Enter your measurements using the requested units.
- Review the estimate and the explanation provided with it.
- Compare results carefully and consult a qualified professional when health decisions are involved.
Understand the result
Health and fitness formulas provide estimates based on population averages and the information you enter. Results can vary with age, sex, body composition, training history, pregnancy stage, medical conditions, medications, and measurement technique.
Health notice: These tools provide general educational estimates and are not medical diagnoses or substitutes for professional care. Seek medical advice for symptoms, pregnancy concerns, medication decisions, or results that worry you.