Calculating your heart rate zone for cardio training

Understanding how to train at the correct heart rate is essential for achieving your cardio goals efficiently. This is a guide to finding the heart rate you should be aiming for during your training.

First, start with choosing your target heart rate zone depending on your goal:

Warm-up / Cool-down 50–60%
Fat burning 60–70%
Long endurance (e.g., marathons) 70–80%
Medium endurance 80–90%
Short endurance (e.g., sprints) 90–100%

Next, there are two ways to use this percentage to calculate your target heart rate.

1. The easy way

Start with 220 and subtract your age to calculate your maximum heart rate. Then take the percentage associated with your training goal (listed above) from this number.

Example: If you are 20 years old, then your maximum heart rate is 220 – 20 = 200 beats per minute. If your goal is burning fat (65%), then your target heart rate is 65% of 200, which is 130 beats per minute.

2. The Karvonen formula

This method is a bit harder to calculate but it takes your level of fitness into account, making it more personalised and more accurate. Here’s how it goes:

  1. You will first need to measure your resting heart rate. The best moment to do this is when you just wake up, before you get out of bed. This number will slowly change as you make progress, but measuring it once a month is fine.
  2. You also need to calculate your maximum heart rate, which is done in the same way as before (220 – your age).
  3. Now take your maximum heart rate and subtract your resting heart rate.
  4. Then take the percentage associated with your training goal (listed above) from this number.
  5. Finally, add your resting heart rate again.

Example: If you are 20 years old, your resting heart rate is 60 beats per minute, and your goal is burning fat (65%), then you calculate it like this:

  • Your maximum heart rate (220 – 20 = 200) minus your resting heart rate is 200 – 60 = 140 beats per minute.
  • Your target percentage (65%) of 140 is 91 beats per minute.
  • Add your resting heart rate again, so 91 + 60 = 151 beats per minute.

Heart rate zone calculator

This calculator uses the Karvonen formula to calculate your target heart rate zone for you!

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