Free tools
Heart rate zone calculator: your five zones and Zone 2
Five heart-rate zones split your effort from very easy to all-out. They are only as good as the number they are built on, so this calculator lets you start from the best one you have: your real maximum, your maximum and resting heart rate, or your lactate threshold. Zone 2, the easy aerobic zone most endurance training should sit in, is highlighted.
Runs in your browser. Nothing you enter is sent or stored.
Short answer
With a known maximum, the five zones are 50–60, 60–70, 70–80, 80–90 and 90–100 % of it. Zone 2 is 60–70 % of your maximum heart rate, or 60–70 % of your heart rate reserve (maximum minus resting) added to your resting heart rate. With a lactate threshold, Zone 2 is about 85–89 % of your threshold heart rate.
Which method to choose
- Threshold fits best if you know your lactate threshold heart rate from a lab, a field test or your watch. Zones anchored to it move with your fitness.
- Heart rate reserve (the Karvonen method) uses your resting heart rate too, so a fit athlete with a low resting heart rate gets zones that start higher.
- % of maximum is the simplest and the model most watches use. Use your observed maximum, not a formula, whenever you can.
Age formulas are averages. 220 minus age and the Tanaka formula (208 − 0.7 × age) can both miss an individual maximum by 10 beats or more, which shifts every zone. If your easy runs keep landing in Zone 3, the zones are the first thing to check.
How to find your maximum and threshold
Your maximum is the highest heart rate you can credibly reach: the end of a 5K race, or a warm-up followed by three hard minutes uphill and a final all-out minute. Ignore single spikes from an optical sensor that don’t match how you felt. For a threshold estimate, run 30 minutes alone as hard as you can hold evenly, and take the average heart rate of the last 20 minutes. Only do maximal efforts when you are healthy and used to hard training, and ask a doctor first if you have a heart condition.
Using your zones
Most endurance coaches suggest spending around 80 % of training time at easy intensity, Zones 1 and 2, and the rest at threshold and above. Read more in our guide to Zone 2 training, and set the same numbers on your watch with heart rate zones on Apple Watch.
Questions
Why are my watch’s zones different?
Apple Watch calculates zones from the maximum heart rate in your health data, or from the values you set manually. Other watches use your threshold or their own estimate. Different anchors give different zones, so pick one source and use it everywhere.
Do zones work for cycling too?
Yes, but heart rate on the bike usually runs a few beats lower than running at the same effort, so cycling zones from a cycling threshold fit better. With a power meter, power zones from your FTP react faster than heart rate.