How this tool works
A target heart rate zone gives you a rough idea of how hard you are working during exercise. This calculator uses the simple approach described by the American Heart Association (AHA).
You enter your age. The tool estimates your maximum heart rate as 220 minus your age. It then works out two zones:
- Moderate intensity: about 50% to 70% of your estimated maximum
- Vigorous intensity: about 70% to 85% of your estimated maximum
Each zone is shown in beats per minute and as a 15-second count. The 15-second count is the per-minute number divided by 4, which is handy if you check your pulse at your wrist and count for 15 seconds instead of a full minute.
You can also enter your resting heart rate if you know it. The tool shows it next to the typical adult resting range of 60 to 100 beats per minute. It does not change the zones.
A worked example
For a 70-year-old:
- Estimated maximum: 220 − 70 = 150 beats per minute
- 50% of 150 = 75; 70% of 150 = 105
- 85% of 150 = 127.5, rounded to 128
| Zone | Beats per minute | 15-second count |
|---|---|---|
| Moderate (50–70%) | 75–105 | about 19–26 |
| Vigorous (70–85%) | 105–128 | about 26–32 |
The 15-second counts come from 75 ÷ 4 = 18.75 (about 19), 105 ÷ 4 = 26.25 (about 26) and 128 ÷ 4 = 32.
To see how these zones fit into a weekly routine, try our exercise goal calculator or read the target heart rate by age guide.
Limits of this tool
"220 minus age" is an estimate. Your true maximum may be higher or lower. Some medicines, for example beta-blockers, lower the heart rate, so these zones may not apply to you at all. Heart rhythm problems can also make pulse counts unreliable. A simple check that works for everyone is the "talk test": during moderate activity you can talk but not sing.
When to talk to your doctor
Ask your doctor what zone is right for you if you take any medicine that affects heart rate, have a heart condition, or are starting a new type of exercise. Talk with your doctor if your resting heart rate is often outside 60 to 100. Stop exercising and call 911 if you have chest pain or discomfort, shortness of breath that does not ease, or feel faint.
Frequently asked questions
Do I need to stay in the zone the whole time?
No. The zone is a guide, not a rule. Warm up and cool down below it, and use how you feel and the talk test along with the numbers.
I take a beta-blocker. Can I use this tool?
You can use it for information, but the zones may be too high for you because these medicines slow the heart. Ask your doctor what effort level is safe, and never change your medicine to reach a target.
How do I check my pulse?
Place two fingers on the inside of your wrist below the thumb. Count the beats for 15 seconds and compare with the 15-second count shown, or multiply by 4 for beats per minute.
Is moderate exercise enough?
For adults 65 and older, the CDC suggests at least 150 minutes a week of moderate activity, or 75 minutes of vigorous activity, or a mix. Moderate activity alone can meet that goal.
Sources
Want the full picture? Read our guide: Target Heart Rate by Age: A Simple Guide for Older Adults.
Read the guideThis tool gives general information for education only. It does not diagnose any condition or replace advice from your doctor, nurse or pharmacist. In an emergency call 911. See our medical disclaimer and sources.