What are heart rate zones?
Heart rate zones are ranges of your heart rate that match a particular training intensity. Training in a specific zone lets you train with purpose: easy endurance work in zone 2 builds your aerobic base, while intervals in zones 4 and 5 improve speed and your ability to sustain a hard pace. Runners, cyclists, swimmers and gym-goers often use zones together with a sports watch or chest strap.
Your maximum heart rate
The zones are based on your maximum heart rate: the highest number of beats per minute your heart reaches at an all-out effort. The best-known estimate is:
maximum heart rate ≈ 220 − age
A newer formula, which research suggests fits older adults slightly better, is the Tanaka formula:
maximum heart rate ≈ 208 − 0.7 × age
Both are averages. For an individual, the true maximum can be 10 to 20 beats higher or lower. If you have measured your maximum, for example in a lab test or a hard, well-structured field test with a heart rate monitor, enter that value.
Two methods
- Percentage of maximum heart rate: each zone is a fixed percentage of your maximum, for example 60–70% for zone 2.
- Karvonen (heart rate reserve): this also uses your resting heart rate. Your heart rate reserve is your maximum minus your resting rate; zones are a percentage of that reserve, added to your resting rate. Fit athletes with a low resting heart rate get zones that suit them better.
zone limit = resting rate + percentage × (maximum − resting rate)
Worked example
You are 40 years old. Using 220 − age, your maximum heart rate is 180.
- Zone 1 (50–60%): 90–108 bpm
- Zone 2 (60–70%): 108–126 bpm
- Zone 3 (70–80%): 126–144 bpm
- Zone 4 (80–90%): 144–162 bpm
- Zone 5 (90–100%): 162–180 bpm
With the Karvonen method and a resting heart rate of 60, zone 2 becomes 60 + 0.6 × 120 = 132 to 60 + 0.7 × 120 = 144 bpm, noticeably higher than with the first method.
The five zones
- Zone 1 – recovery: walking, cool-downs, very easy cycling. You can talk easily.
- Zone 2 – endurance: the easy pace you can keep up for a long time, and the backbone of most training plans.
- Zone 3 – tempo: a steady, comfortably hard effort; you can speak in short sentences.
- Zone 4 – threshold: hard, around your lactate threshold. Talking is difficult.
- Zone 5 – maximum: short, very intense efforts such as sprints.
Measuring your resting heart rate
Measure your resting heart rate in the morning right after waking, while still lying down. Count your pulse for 30 seconds and multiply by 2, or use a sports watch. Repeat for a few days and take the average. For adults the resting heart rate is usually between 60 and 100 bpm; trained endurance athletes can be lower.
Use the pace calculator to work out your running pace, and the calorie calculator for your daily energy needs. If you have heart problems, take medication that affects your heart rate or are returning to exercise after a long break, check with your doctor first.
Frequently asked questions
How do I calculate my maximum heart rate?
A common estimate is 220 minus your age. The Tanaka formula is 208 minus 0.7 times your age. A measured value is always more accurate.
Which zone should I train in?
For general fitness and endurance, spend most of your training time in zone 2. Use the higher zones for short intervals.
What is the Karvonen method?
A method that includes your resting heart rate: zone limit = resting rate + percentage × (maximum − resting rate).
Why doesn't my watch match the calculator?
Watches may use a different formula, their own zone limits or a measured maximum. Wrist sensors can also be less accurate during intense effort.
What is a good resting heart rate?
For adults usually between 60 and 100 bpm. Lower values are normal in fit people.
Do the formulas work for everyone?
No, they are estimates. With heart conditions or medication such as beta blockers, the zones are not reliable; consult a doctor.
Last reviewed: 2026-10-06. Results are estimates for information only.