Below are some useful health metric related calculators

BMI Calculator
BMR Calculator
HR Max and zone calculator

Body mass index (BMI) can sometimes be useful to determine your height to weight ratio. It can also be misleading depending on your body type.

Basal Metabolic Rate is the amount of calories burned during a day just to function. This value excludes any physical activity you perform. It’s a useful value to know when determining your daily caloric intake.

Predicted max heart rate and intensity zone values are useful to know if you are using a heart rate monitor to gauge the intensity levels of your activity.