STEP 1: Find you PMHR in beats per minute by subtracting your age from 220: tuberacun serat her ས ་ 220 - (Your Predicted Maximum Heart Rate) Example: 220 - 15 = 205 (PMHR of a 15 year-old individual) STEP 2: Work out your lowest Target Heart Rate that you need to aim for during the exercise by multiplying your PMHR by 60% (or .6): (PMHR) X 60% (or 6) = (Lowest Target Hear Rate) Example: 205 x .6 = 123 beats/minute (Lowest THR of 15 year-old individual) STEP 3: Work out for your Highest Target Heart Rate that you can aim for during the exercise by multiplying your PMHR by 80% (or .8): (PMHR) x 80% (or .8) = (Highest Target Hear Rate) Example: 205 x.8 = 164 beats/minute (Highest THR of 15 year-old individual)​