The simplest way of doing this is to take 220(if male) 226(if female) minus your age and this will be your maximum heart rate.. for example say you are 30, so 220-30 = 190. 190 beats per minute is your max heart rate.
These are the different heart rate zones you should look at when exercising.
healthy heart rate is 60% to 70% of your Max Heart Rate lighter activity is said to promote a healthy stronger heart and good at burning fat while recovering from more intense workouts.
Aerobic is 70% to 80% of your MHR and helps build up endurance, heart and lungs..
Anaerobic is 80% to 90% of MHR , high intensity ... helps body work with lactic acid build up,(muscle fatigue) being explosive.. sprinting,, throwing punch combinations...
After you become more fit or are already in good conditioning and train 3 or more times a day there is another way to find your MHR that may be a little more accurate
205 minus half of your age. so again if you are 30 half is 15, and 205 - 15 = 190
females can use 211 instead for this formula .. they are pretty close to one another infact in this age both give 190 MHR but if you were say 20 years old the first would give 200MHR and the latter would be 195 MHR again very close to the same..
Also find your resting heart rate to start out.. say when you first wake up.. and an easy way to tell if your body has recovered from a previous days work out is to take it the next day and if its 10 or more bpm higher than normal your body is still recovering so take it slow or rest..