Fitness & Health Calculators
Understand your body with standard, peer-reviewed formulas. Results are estimates for healthy adults and are not a substitute for medical advice.
- BMI CalculatorCalculate your Body Mass Index (BMI) in metric or US units, see your weight category and the healthy weight range for your height.
- BMR CalculatorEstimate your Basal Metabolic Rate with the Mifflin-St Jeor, Harris-Benedict or Katch-McArdle formula, plus daily calories for each activity level.
- Calorie CalculatorFind out how many calories you need per day to maintain, lose or gain weight based on your age, sex, height, weight and activity level.
- Body Fat CalculatorEstimate body fat percentage with the U.S. Navy method using neck, waist and hip measurements, plus a BMI-based estimate and fat category.
- Ideal Weight CalculatorFind your ideal body weight using the Robinson, Miller, Devine and Hamwi formulas, plus the healthy weight range based on BMI.
- Macro CalculatorCalculate your daily protein, carbohydrate and fat targets in grams from your calorie needs and goal, with balanced, low-carb and high-protein splits.
- Pace CalculatorCalculate running pace, finish time or distance. Enter any two values to find the third and see split times for 5K, 10K, half marathon and marathon.
- Pregnancy Due Date CalculatorEstimate your baby's due date from your last period, conception date or IVF transfer date, and see how many weeks pregnant you are today.
- Water Intake CalculatorEstimate how much water you should drink per day from your weight, exercise time, climate and pregnancy or breastfeeding, in liters, cups and ounces.
- One Rep Max CalculatorEstimate your one rep max (1RM) from the weight and reps you can lift using the Epley, Brzycki and other formulas, plus a table of training percentages.
- Heart Rate Zone CalculatorFind your maximum heart rate and the five training zones from your age, or use your resting heart rate with the Karvonen method for a personal result.
- Lean Body Mass CalculatorEstimate your lean body mass with the Boer, James and Hume formulas from your sex, height and weight, or from a known body fat percentage.
- Sleep CalculatorFind the best time to go to bed or wake up based on 90-minute sleep cycles, so you wake between cycles and feel rested instead of groggy.