Free health tools
No account, no login. The calculations use the same coefficients as the fjt app and run in your browser.
- Biological age calculatorFrom sleep, steps, training, smoking and body measurements. Heart rate optional.
- VO₂max calculatorNTNU (HUNT) non-exercise formula — no running test needed.
- Resting heart rate chartResting heart rate ranges by age and sex, with your own value classified.
Body measurements
- Waist-to-Hip Ratio CalculatorEnter your waist and hip measurements to see your waist-to-hip ratio and how it compares with the WHO risk cut-off.
- Body Fat CalculatorEstimate your body fat percentage from height, waist and neck (plus hips for women) using the U.S. Navy method.
- BMI CalculatorCalculate your BMI from height and weight, see your WHO category, and learn what BMI doesn't show.
- Ideal Weight CalculatorEnter your height to see the healthy weight range that matches the WHO normal BMI band (18.5–24.9).
Energy and nutrition
- BMR CalculatorEstimate the energy you burn at rest and your daily calorie needs by activity level, using age, height, weight and sex.
- Protein CalculatorCalculate your daily protein needs in grams based on your weight and lifestyle.
- Water Intake CalculatorCalculate your daily total fluid need and how much should come from drinks, based on sex and exercise time.