Health & Fitness Calculators
30 free calculators.
BMIEstimate body mass index from weight and height, a quick screening number, not a full health picture.BMI PrimeExpress BMI as a ratio to the upper healthy limit of 25, so 1.0 marks that boundary.BMREstimate basal metabolic rate, the energy used at rest, with the Mifflin-St Jeor equation.Bedtime From Wake TimeWork backwards from a wake time in whole 90-minute sleep cycles to find a bedtime.Body Fat Estimate (Navy Method)Estimate body fat percentage from tape measurements using the US Navy circumference method.Calories Burned RunningEstimate running energy use from weight, time and running intensity.Calories Burned WalkingEstimate walking energy use from weight, distance and walking speed.Carb Grams From CaloriesConvert a carbohydrate calorie share into grams for meal planning.Cycling Calories BurnedEstimate cycling energy use from weight, time and riding effort.Cycling Speed and TimeConvert between cycling distance, time and average speed in one step.Daily Calorie NeedsTurn a maintenance estimate into a daily target for losing, maintaining or gaining weight.Heart Rate ZonesSplit exercise intensity into five heart-rate zones from age-based maximum heart rate.Hydration After ExerciseEstimate fluid to drink after exercise from weight lost during the session.Ideal Weight (Devine Estimate)Estimate a reference weight with the Devine formula, shown as a range because one number is misleading.Lean Body MassEstimate lean body mass from total weight and body fat percentage.Macro SplitSplit daily calories into protein, carbohydrate and fat grams from percentage targets.Max Heart RateEstimate maximum heart rate two ways: the classic 220 minus age and the Tanaka formula.One-Rep Max EstimateEstimate a one-repetition maximum from a lighter set using the Epley formula.Protein NeedsEstimate daily protein in grams from body weight and activity level.Running PaceWork out pace per kilometre and speed from a run's distance and time.Running TimePredict how long a run will take from distance and target pace.Sleep CyclesTurn a sleep duration into 90-minute sleep cycles and nearby cycle-friendly durations.Sleep Debt (Rough)Add up the shortfall when nightly sleep falls below what you need, over several nights.Step DistanceConvert a step count into distance using an estimated stride length.TDEEEstimate total daily energy expenditure by multiplying BMR by an activity factor.Target Heart RateFind a target heart rate for a chosen intensity using the Karvonen method with resting heart rate.Waist-to-Height RatioDivide waist by height; keeping the result under 0.5 is a common rough guide.Waist-to-Hip RatioDivide waist by hip measurement for a simple fat-distribution indicator.Walking TimeWork out how long a walk will take from distance and walking speed.Water IntakeEstimate daily water intake from body weight, with extra for exercise.