Free Fitness and Health Calculators
34 free tools for pace, endurance, strength, gym planning, nutrition, body composition, calories, weight goals, water, creatine, sleep, and fitness age. Each page names its formula, explains the limits, and keeps every entry private in your browser.
Reviewed by Chris Pruitt, Certified ASFA Personal Trainer. Updated September 3, 2026.
Nutrition
3 toolsFind your daily protein target and see how far your current intake is from it.
Open calculator →NutritionFree Macro CalculatorEstimate daily calories, protein, carbs, and fat for cutting, maintaining, or gaining.
Open calculator →NutritionKeto Macro CalculatorSet a low carb ceiling and calculate protein, fat, and total calories for a keto style plan.
Open calculator →Body Composition
4 toolsEstimate fat free mass index, normalized FFMI, and rough muscle potential.
Open calculator →Body CompositionBody Fat Percentage CalculatorUse the U.S. Navy circumference equations to estimate body fat from a tape measure.
Open calculator →Body CompositionArmy Body Fat CalculatorCheck the current 2026 Army waist to height standard with the official cutoff.
Open calculator →Body CompositionWaist to Hip Ratio CalculatorCalculate waist to hip ratio and compare it with population risk bands for men and women.
Open calculator →Calories Burned
4 toolsEstimate calories for common training, sports, and daily activities with published MET values.
Open calculator →Calories BurnedTreadmill Calorie CalculatorCalculate treadmill calories with speed, grade, body weight, and the ACSM walking or running equation.
Open calculator →Calories BurnedSteps to Calories CalculatorTurn a step count into distance, walking time, and calories using your height and weight.
Open calculator →Calories BurnedCalories Burned Walking CalculatorEstimate walking calories from distance or time, pace, weight, and optional incline.
Open calculator →Weight Goals
3 toolsCompare Devine, Robinson, Miller, Hamwi, and the healthy BMI range side by side.
Open calculator →Weight GoalsWeight Loss Percentage CalculatorSee pounds lost, percentage lost, and progress toward the five and ten percent marks.
Open calculator →Weight GoalsGoal Weight Date CalculatorTurn a daily calorie deficit into a best case calendar date and weekly loss rate.
Open calculator →Water and Creatine
3 toolsEstimate daily fluid from weight, exercise time, climate, and current intake.
Open calculator →Water and CreatineCreatine CalculatorCalculate a loading dose, four daily loading portions, and a practical maintenance dose.
Open calculator →Water and CreatineHow Much Water Should I Drink on CreatineEstimate base fluid and add a modest practical adjustment for loading or maintenance.
Open calculator →Sleep and Age
3 toolsFind bedtimes or wake times from average sleep cycles and a 15 minute sleep onset estimate.
Open calculator →Sleep and AgeSleep Debt CalculatorAdd up two weeks of short nights and estimate a gradual repayment plan.
Open calculator →Sleep and AgeFitness Age CalculatorEstimate VO2 peak with the published HUNT model and compare it with measured age norms.
Open calculator →Pace and endurance
5 toolsConvert MPH or KPH to pace and finish time.
Open calculator →Pace and enduranceSwim Pace CalculatorFind 100 meter, 100 yard, and 50 meter splits.
Open calculator →Pace and enduranceGrade Adjusted Pace CalculatorEstimate flat equivalent pace for a steady hill.
Open calculator →Pace and enduranceRowing Pace CalculatorConvert rowing distance and time to split and watts.
Open calculator →Pace and enduranceRun Walk Pace CalculatorBlend run and walk intervals into one average pace.
Open calculator →Fitness estimates
3 toolsEstimate VO2 max from a 12 minute run distance.
Open calculator →Fitness estimatesStationary Bike Calorie CalculatorEstimate exercise bike calories from MET intensity.
Open calculator →Fitness estimatesExercise MET CalculatorConvert oxygen uptake to METs and estimated calories.
Open calculator →Strength training
2 toolsBody measurements
1 toolGym Equipment Calculators
3 toolsAdd equipment, flooring, delivery, storage, and tax.
Open calculator →Gym Equipment CalculatorsGym Plate CalculatorFind matching plates per side for a target load.
Open calculator →Gym Equipment CalculatorsLeg Press Weight CalculatorEstimate moving load and gravity based vertical equivalent for an angled leg press.
Open calculator →How these calculators work
Each tool uses the published method named on its page. Every result is an estimate. The pages explain normal error, show real sources when a research based method is involved, and state when medical or official assessment matters more. Nothing entered is stored, sent, or transmitted.