Heart Rate Zone Calculator

Where this fits with your broader training plan

Heart rate zones are usually one piece of a larger training picture. If you are preparing for a race, the Marathon Finish Time Calculator can help you set a target pace that lines up with the aerobic zones described above, so your training pace and your heart rate response stay reasonably aligned as your fitness improves.

If you want a more direct fitness benchmark alongside your heart rate zones, the Cooper Test Calculator estimates VO2 max from a 12 minute run, while the VO2 Max Runners Calculator estimates it from a recent race time and also produces training pace zones, giving you a second, independent way to check whether your effort levels match your actual fitness.

Since the calorie estimates on this page are only a rough starting point, pairing them with the TDEE Calculator can help you see how that exercise related burn fits into your total daily energy needs, rather than looking at a single workout's calories in isolation.

A full worked example

Take a 35 year old using the standard formula. Max heart rate works out to 220 minus 35, or 185 beats per minute. Without a resting heart rate entered, Zone 2, the light aerobic and fat burning zone at 60 to 70 percent, spans roughly 111 to 130 beats per minute, calculated directly as a percentage of that 185 maximum.

Now suppose that same person enables the Karvonen method and enters a resting heart rate of 58 beats per minute. Heart rate reserve becomes 185 minus 58, or 127 beats per minute. Zone 2 under Karvonen is calculated as 60 to 70 percent of that 127 reserve, then added back to the 58 resting rate, giving a range of roughly 134 to 147 beats per minute. Notice how much higher this range sits compared to the simpler percentage of max heart rate method, which is a common surprise for people trying Karvonen zones for the first time after using standard zones for years.

For the calorie estimate, a 75 kilogram person exercising in Zone 3 at roughly 7 METs burns approximately 7 times 3.5 times 75, divided by 200, which comes out to about 9.2 calories per minute, or around 275 calories over a 30 minute session. Heavier body weights and higher intensity zones both push that number up, which is why the estimate changes noticeably between Zone 1 and Zone 5 even at the same body weight.

A quick note on safety

Heart rate zone estimates are useful for general training guidance, but they are not a substitute for medical advice, particularly for anyone with a heart condition, a family history of cardiac issues, or anyone starting a new exercise program after a long period of inactivity. If you experience chest pain, unusual shortness of breath, dizziness, or an irregular heartbeat during exercise, stop and seek medical attention rather than pushing through toward a target zone.

A heart rate monitor, whether a chest strap or a wrist based sensor, will always give you a more accurate real time reading than any formula based estimate, since individual variation in fitness, medication, sleep, hydration, and stress can all shift your actual heart rate response on a given day.