In order to get the most out of your workout, you’ll need to know how to calculate your target heart rate. If your heart rate isn’t high enough, you may need to push yourself a bit harder. If it’s too high, you’ll need to ease up. There are several ways to calculate target heart rate which give you a ball park figure. This method is one of the more accurate.

1. Find your resting heart rate (RHR). To best calculate your resting heart rate, check your pulse as soon as you wake up. You might want to do this for a few days and find the average for the most accurate result (you know, just in case you were having a really good dream that might skew your results). To find the average, add your pulse numbers up and divide by the number of times you measured it. For example, if you took your pulse three mornings and your pulse was 78, 80 and 82, you would add those three numbers for a result of 240. You would then divide that by three because you took your pulse three times. This number will give you your average resting heart rate (RHR). In this case, it would be 80.
2. Find your maximum heart rate (MHR). The next step in calculating your target heart rate is finding your maximum heart rate (MHR). To do this, just subtract your age from 220. For example, if you’re 35, your MHR is 185. Simple enough, right?
3. Find your heart rate reserve (HRR). Now subtract your RHR from your MHR In this case, it would be 185 minus 80, or 105. This number is your heart rate reserve (HRH).
4. Find the lower limit of your THR zone. To find the lower limit of your target heart rate zone, you’ll first find 60 percent of your HRR number (in case percentages aren’t your forte, just grab a calculator and multiply by 0.6.). Then, add your RHR. In this scenario, you would first calculate 105  times 0.6 for a result of 63. Then add 80, for a lower end target heart rate of 143.
5. Find the upper limit of your THR zone. Now for the higher end of your target heart rate. For this number you find 80 percent (that’s 0.8) of your HRR and add your RHR. Here that would be 105 times 0.8 plus 80, for an upper limit of 164.
6. Find your target heart rate (TRH). Finally! If you add the upper and lower numbers and divide by two, you’ll have your average target heart rate (143 plus 164, divided by two is 153.5). This final number will give you a good number to shoot for. But it’s a good idea to keep that upper number in mind so you don’t overshoot by too much.

As mentioned before, this isn't the only way to figure out your THR. Some sources will tell you that you only need to find 70 to 85 percent of your MHR, and other sources say your higher THR zone limit is 90 percent, rather than 80.  No amount of math will give you a perfect target heart rate, as the numbers don’t take into consideration your health conditions, weight and other factors. It’s always a good idea to check with a doctor before starting a strenuous exercise routine. But once you have your doc’s okay, figuring out your target heart rate can be a valuable tool to help you get fit.