The easiest and best known method for calculating your maximum heart rate is to subtract your age from 220.

Basic Formula
Max Heart Rate = 220 – Age

While this calculation is sufficient for most purposes, recent research has shown that the relationship between a person’s maximum heart rate and age is not linear. Hence, there are a number of other methods for calculaitng your maximum heart rate as well.

A University of Missouri-Columbia suggests an alternative formula of
MHR=206.3 – (0.711 × Age)

An Indiana University study recommends using the formula
MHR=217 – (0.85 × Age)

There are number of max heart rate calculators available on the internet.