Heart rate zone calculator

Which max heart rate formula should you use?

Every formula here is an average fitted to large groups, so any one person can be 10–15 beats off in either direction. That's worth knowing before you build a training plan on it.

• 220 − age is the classic, easy to remember, but it tends to underestimate max heart rate in older adults.
• Tanaka (208 − 0.7 × age) came from a large 2001 meta-analysis and holds up better across ages. It's the default here.
• Gulati (206 − 0.88 × age) was derived from a large study of women and is a better starting point for many women.

If you've done a proper max test or seen a clearly higher number on a hard race finish, enter it in the "known max" box. For the long story, read is 220 minus your age accurate?

Percent of max vs Karvonen

The simple method takes a percentage of max heart rate. The Karvonen method uses your heart rate reserve instead: max HR minus resting HR. Zone limits are then resting HR + reserve × percentage. Because it accounts for how low your resting heart rate is, Karvonen gives higher, more realistic zones for fit people. If you know your resting heart rate, it's usually the better choice. Not sure what's normal? See what's a normal resting heart rate?

What each zone is for

Zone	% of max HR	Used for
1 — Recovery	50–60%	Warm-ups, cool-downs, easy days after hard sessions
2 — Endurance	60–70%	Building aerobic base; the bulk of training for most endurance athletes
3 — Tempo	70–80%	"Comfortably hard" steady runs and rides
4 — Threshold	80–90%	Intervals that raise the pace you can sustain
5 — Max	90–100%	Short, very hard repeats; used sparingly

For general health, public health guidance counts moderate activity at roughly 50–70% of max heart rate and vigorous at roughly 70–85%. For why zone 2 gets so much attention, read zone 2 heart rate: how to find it and heart rate zones explained.

Worked example: a 35-year-old

• 220 − age: 185 bpm max
• Tanaka: 208 − 0.7 × 35 = 183.5 bpm (about 184)
• Zone 2 by % of max: 60–70% of 184 = 110–128 bpm
• Zone 2 by Karvonen with a resting HR of 60: 60 + (183.5 − 60) × 0.6 to 0.7 = 134–146 bpm

Same person, same zone, very different numbers. The Karvonen range is usually closer to what an easy conversational pace feels like for someone who exercises regularly. When in doubt, trust the talk test.

Getting accurate numbers

• Resting HR: take it on waking, lying still, over a few mornings, and use the average.
• Chest straps beat wrist sensors during intervals; wrist readings can lag or pick up your cadence.
• Medications matter. Beta blockers and some other drugs lower heart rate, so formula-based zones won't fit. Ask your doctor.
• Don't max-test yourself if you're new to exercise or have any heart symptoms; get medical clearance first.

Frequently asked questions

How do I calculate my heart rate zones?

Estimate your maximum heart rate (for example 208 − 0.7 × age), then take percentages of it: zone 1 is 50–60%, zone 2 is 60–70%, zone 3 is 70–80%, zone 4 is 80–90% and zone 5 is 90–100%. With the Karvonen method you apply those percentages to max HR minus resting HR, then add resting HR back.

What is my zone 2 heart rate?

Roughly 60–70% of your maximum heart rate, or higher if you use the Karvonen method. For a 35-year-old that's about 110–128 bpm by % of max, or around 134–146 bpm by Karvonen with a resting HR of 60.

Is 220 minus age accurate?

It's a rough average. Individuals can differ by 10–15 bpm, and it tends to underestimate max heart rate in older people. The Tanaka formula (208 − 0.7 × age) is usually a better estimate.

What is the Karvonen formula?

Target HR = resting HR + (max HR − resting HR) × intensity. It uses your heart rate reserve, so it adjusts zones for how fit you are.

What heart rate is too high during exercise?

Briefly reaching your maximum during hard efforts is normal for healthy people. Stop and seek medical advice if you have chest pain, dizziness, unusual breathlessness or a heart rate that stays very high at rest.