Health and Fitness Calculators

Calculators for body, nutrition, fitness, sleep and pregnancy, each based on a published method such as the CDC's BMI categories, the US Navy body fat formula or the Mifflin-St Jeor calorie equation. Each page explains the method and its limits. They're estimates to help you plan, not medical advice.

26 free calculators · no sign-up

Most used

BMI CalculatorBody Mass Index in US or metric units.Calorie CalculatorDaily calorie needs (TDEE) and BMR.Due Date CalculatorEstimated due date and weeks pregnant.Ovulation-Based Due DateDue date from ovulation or conception date.Body Fat CalculatorBody fat percentage from a tape measure (US Navy method).

Body and nutrition

Weight, body fat, calories and macros.

BMI CalculatorBody Mass Index in US or metric units.Body Fat CalculatorBody fat percentage from a tape measure (US Navy method).Ideal Weight CalculatorIdeal body weight by four formulas, plus a healthy BMI range.Calorie CalculatorDaily calorie needs (TDEE) and BMR.TDEE CalculatorMaintenance calories by three formulas and every activity level.Macro CalculatorDaily protein, carbs and fat for your goal, per day and per meal.Weight Loss CalculatorDaily calories and a realistic date to reach your goal weight.BMR CalculatorCalories you burn at rest, by three formulas.Calorie Deficit CalculatorDaily calories to reach a goal weight by a date.Protein Intake CalculatorGrams of protein a day for your weight and goal.Water Intake CalculatorHow much water to drink a day, with exercise and heat.Blood Alcohol (BAC) CalculatorEstimated BAC from drinks, weight and time.A1C CalculatorConvert A1C to average blood sugar (eAG), and back.

Fitness and sleep

Running pace and better bedtimes.

Running Pace CalculatorPace per mile and km for any distance.Calories Burned CalculatorCalories burned for 24 activities, by weight and time.One Rep Max CalculatorEstimate your 1RM and training weights from any set.Heart Rate Zone CalculatorYour 5 training zones, max and zone 2 heart rate.Steps to Miles CalculatorSteps to miles and kilometers by height.Sleep CalculatorBest times to go to bed or wake up.Race Time PredictorPredict your 10K, half or marathon time from a recent race.Sleep Debt CalculatorHow much sleep you're short this week, and how to make it up.

Pregnancy and fertility

Due dates and fertile windows.

Due Date CalculatorEstimated due date and weeks pregnant.Ovulation-Based Due DateDue date from ovulation or conception date.How Far Along Am I? Pregnancy Week CalculatorWeeks pregnant, trimester and upcoming milestones.Pregnancy Weight Gain CalculatorRecommended weight gain for your BMI, week by week.Ovulation CalculatorYour likely fertile days and next period.

Quick answers

Ready-made results for the most common searches.

Questions about health and fitness calculators

Is BMI or body fat percentage more accurate?

Body fat percentage says more about health because BMI can't tell muscle from fat. BMI is quicker and is still a useful screening number for most adults.

Can I rely on these for medical decisions?

No. They use standard published formulas and are good for planning and tracking, but your doctor or midwife should guide medical decisions.

💪 Health and Fitness Calculators