Heart Rate Zone Calculator
Find your five training heart rate zones with the Karvonen method, which uses your resting heart rate as well as your max.
Measure right after waking, before getting out of bed.
What are heart rate zones?
Heart rate zones are ranges of beats per minute that line up with how hard you're working. Training by zone lets you keep easy days easy and hard days hard: low zones build aerobic endurance and help recovery, while high zones train speed and your ability to sustain hard efforts. Most training plans and fitness watches use five zones.
How the Karvonen method works
The Karvonen method, published by Finnish researcher Martti Karvonen and colleagues in 1957, sets zones as a percentage of your heart rate reserve — the gap between your resting and maximum heart rate — rather than a percentage of max heart rate alone:
Target heart rate = resting HR + (max HR − resting HR) × intensity %
Because resting heart rate usually drops as aerobic fitness improves, two people of the same age can get different zones. That makes Karvonen zones more personal than simple percentage-of-max zones. The American College of Sports Medicine uses heart rate reserve too: roughly 40–59% counts as moderate intensity and 60–89% as vigorous.
Estimating your max heart rate
A true max heart rate comes from an all-out test, ideally supervised. Without one, this calculator can estimate it from age. 208 − 0.7 × age comes from a 2001 analysis of over 18,000 people by Tanaka, Monahan, and Seals, and tends to be more accurate than the older 220 − age rule, which overestimates max heart rate in younger adults and underestimates it in older adults. Even so, any individual can differ from either estimate by 10 bpm or more, so use a measured value if you have one.
How to use this calculator
Choose how to set your max heart rate, enter your age or a known max, and add your resting heart rate. For the most accurate resting value, count your pulse for a full minute right after waking, before getting out of bed, and average it over a few mornings — or use the resting figure from a fitness watch. Press Calculate zones to see the beats-per-minute range for each zone.
Using your zones
Many endurance plans put most weekly training in zones 1–2 (easy, conversational effort), with smaller amounts in zones 3–4 for tempo and threshold work, and short intervals in zone 5. Zone names and exact boundaries differ between coaches and watch brands, so compare the bpm ranges rather than the labels. Heart rate also lags behind effort at the start of an interval and drifts upward in heat or during long sessions.
Limitations
These zones are estimates. Medications such as beta blockers, illness, caffeine, heat, dehydration, and poor sleep all change heart rate. If you have a heart condition, take medication that affects heart rate, or are new to vigorous exercise, talk to a doctor before training at high intensities. See the Disclaimer for details, and try the Running Pace Calculator to plan the runs themselves.