How to find your heart rate and know your rate for fat loss?

During cardio activities, like karate, I%26#039;m told to have your heart rate at a certain percentage. What percentage is right for fat loss during cardio activities?

How do I figure out my max. heart rate?

How do you figure out your heart rate without a heart rate monitor (like the belt or watch thingys). I think you count the times your heart beats for 6 seconds and multiply it by 10.

Thanks to anyone who can help.

How to find your heart rate and know your rate for fat loss?

Giant Eagle Marc%26#039;s