Your 5 training zones from max & resting HR
Maximum heart rate is estimated as 220 minus your age. If you enter a resting heart rate, the Karvonen method is used: each zone is a percentage of your heart-rate reserve (max minus resting) added back on top of resting. That fits fitter people better than a plain percentage of max.
Count your pulse for a full minute right after waking, before getting out of bed, and average it over a few days.
Zone 2 uses a higher share of fat for fuel and can be sustained for long sessions, which is why endurance plans favour it.
It is a population average and can be off by 10 or more beats for an individual. A supervised test gives a true maximum.
Body mass index & health status
Exact age in years, months & days
Daily calorie needs (TDEE / BMR)
Healthy weight range for your height
Estimate your fertile window & next period
Daily protein target for your weight & goal