About this tool
Heart Rate Zones
Heart Rate Zones calculates the five aerobic training zones from your age or a custom maximum heart rate, using either the percentage-of-max method or the Karvonen heart rate reserve method.
How to use it
- Enter your age, or a measured maximum heart rate if you have one.
- Add your resting heart rate to use the Karvonen method.
- Choose the method and read your five zones.
Percentage of max versus Karvonen
The simple method takes percentages of your maximum heart rate. Karvonen works from heart rate reserve instead: maximum minus resting, then a percentage of that range added back to resting. Karvonen accounts for fitness, because a fitter person with a lower resting rate gets different zone boundaries.
Both depend on knowing your true maximum. The familiar 220 minus age formula is a rough population average with a standard deviation of around ten to twelve beats, so for any individual it can easily be out by that much in either direction.
Worked example
The default age with the simple method:
- Age35
- Estimated max HR220 - 35 = 185
- Zone 2 (60-70%)about 111 to 130 bpm
Result: Zone 2 is the easy conversational pace that most endurance training should sit in.
When it helps
- Setting training zones for structured endurance work.
- Checking whether your easy runs are genuinely easy.
- Getting more accurate zones by using a measured max rather than the age formula.
- Understanding zone numbers your watch reports.
Common mistakes
- Trusting 220 minus age as your actual maximum. A field test or a lab test gives a far better number.
- Training everything in zone 3. The common pattern is easy days too hard and hard days too easy, which produces less adaptation than either done properly.
- Comparing your heart rate to someone else's. Maximum heart rate is individual and is not a fitness measure.
What this tool handles
- General fitness information, not medical advice. Check with a doctor before starting intense exercise, especially with any cardiac history.
