Heart rate zone calculator
Enter your age below to get all five heart rate zones. Zone 2 — the aerobic base zone most endurance plans are built around — sits at 60–70% of your maximum heart rate. The calculator uses the Tanaka formula (208 − 0.7 × age), which predicts maximum heart rate more accurately across adult ages than the older 220 − age rule.
Estimated max heart rate: 184 bpm
| Zone | % of max | Range (bpm) | What it is for |
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How the formula works
Your training zones are percentages of your maximum heart rate, so everything depends on estimating that maximum. Two formulas are in common use:
- 220 − age. Widely quoted, easy to remember, and systematically off at the ends of the age range — it underestimates maximum heart rate in adults over 50 and overestimates it in the young.
- Tanaka: 208 − 0.7 × age. Published by Tanaka, Monahan and Seals in 2001 from a meta-analysis of 351 studies covering 18,712 subjects, then validated on 514 healthy adults. It fits observed data better across the adult lifespan, particularly over 40. This calculator uses it.
Neither escapes the roughly ±7–12 bpm of individual variation inherent in any age-based estimate. Tanaka is the better formula; it is not a precise one.
A formula cannot know your individual physiology; only a properly conducted maximal test or a lab lactate test can. Treat the numbers above as a starting range and adjust from how efforts actually feel.
Why Zone 2 gets all the attention
Zone 2 sits at 60–70% of maximum — easy enough to hold a conversation, hard enough to be training. It builds aerobic capacity and mitochondrial density with a low recovery cost, which is why endurance plans spend most of their volume there and why it dominates training discussion.
The common mistake is drifting up. Zone 2 done at Zone 3 intensity accumulates fatigue without the adaptation benefit, and because it feels productive, it is easy to do for weeks before noticing the cost in your recovery metrics.
Setting zones on an Apple Watch
watchOS calculates zones automatically from your health data and date of birth. To use the values above instead, open the Watch app → My Watch → Workout → Heart Rate Zones, switch from Automatic to Manual, and enter the limits for zones 2, 3 and 4.
Track Zone 2 automatically
Body Vitals tracks weekly Zone 2 minutes alongside readiness, HRV and training load — on your home screen, entirely on-device.
View on the App StoreFrequently asked questions
What is Zone 2 heart rate?
Zone 2 is 60-70% of maximum heart rate — an easy, conversational aerobic pace. It is the zone most endurance training plans build base volume in, because it develops aerobic capacity with relatively little recovery cost.
Is 220 minus age accurate?
It is a rough approximation that systematically underestimates maximum heart rate in adults over 50. The Tanaka formula (208 - 0.7 x age), from a 2001 meta-analysis of 351 studies, fits observed data better across the adult lifespan — though both carry roughly 7-12 bpm of individual variation.
How does the Apple Watch calculate heart rate zones?
watchOS estimates your zones automatically from your health data and date of birth. You can override them manually in the Watch app under My Watch > Workout > Heart Rate Zones by switching from Automatic to Manual.
How do I know if I am really in Zone 2?
The talk test is the practical check: in Zone 2 you can speak in full sentences but would rather not sing. If you are gasping between words you have drifted into Zone 3. For a precise figure, a lactate test or a properly conducted max-HR test beats any formula.