HR Zones is a simple to use heart rate training zone calculator. All you need to do is pick your date of birth, and it will calculate the five distinct heart rate zones for different types of training outcomes based on the percentage of your maximum heart rate.
Your estimated maximum heart rate is calculated as 220 less your age as per the following resource https://www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm#:~:text=You%20can%20estimate%20your%20maximum,beats%20per%20minute%20(bpm).
It is very important to consult your general practitioner before undertaking any sort of exercise to ensure that you are medically fit to do so. This is a simple calculator, not a replacement for sound medical advice, so please treat your health with the caution and respect that it deserves.