Health tools

Free health calculators

Simple, science-based tools to understand your body and set the right targets. All free, no sign-up.

BMI Calculator

Body Mass Index (BMI) is a quick screening measure of weight relative to height. Enter your height and weight to find your BMI and category.

Estimate your body fat percentage using the US Navy circumference method. You'll need a measuring tape for your neck, waist and (for women) hips.

Carbohydrates fuel your training. This tool estimates your daily calorie needs (Mifflin-St Jeor), then recommends a carb range for your goal.

Protein is the building block of muscle. Find out how many grams per day you should aim for, based on your weight, activity and goal.

Hydration drives performance and recovery. Estimate your daily water needs from your body weight and training time.