How do you know if your hrm is accurate?

How can you know if your heart rate monitor is accurate?

Stick your finger in your neck and count.

I assume you are not talking about your heart beat. You probably want to know about your calorie burn. If so, all HRMs utilize their own algorithm for calculating a calorie burn from a heart rate. They really don't know how many calories you burn. They are called a Heart Rate Monitor, not a Calorie a Burn Monitor. There is a reason for that.

Anyway, one of our members took the time to write up a good synopsis on HRMs. http://www.myfitnesspal.com/blog/Azdak/view/the-real-facts-about-hrms-and-calories-what-you-need-to-know-before-purchasing-an-hrm-or-using-one-21472