hrm question

Hardemanwifey

I got a new HRM for xmas and i'm trying to make sure it's set up righ. Its a sportline cardio 680 and it wants me to set up different levels of my maximum heart rate. It has an option to use the automatic settings but Idk if that's correct for me. Level 1 shud be 55-70% of my max heart, level 3 shud be like 80-100% of max heart rate. So shud I take my max heart rate and multiple by the different % for each levels. Plz help. Thanks so much. Hope everyone had a nice holiday