Heart Rate Zones Calculator
Your zones are personal: they depend on your maximum and resting heart rate, not a chart on the gym wall. Get all five zones in both common methods.
How to use this calculator
- Measure your resting heart rate in the morning, right after waking — that single number sharpens everything.
- Enter your age; we estimate max heart rate with the Tanaka formula (208 − 0.7 × age).
- Use the Karvonen column for training targets — it accounts for your resting rate, %-of-max does not.
How your zones are built
Maximum heart rate is estimated with the Tanaka formula (2001), which fits measured data better than the old 220 − age:
max HR = 208 − 0.7 × ageTwo ways to turn that into zones. % of max is the simple chart method. Karvonen (heart-rate reserve) anchors to your resting heart rate and matches perceived effort much better:
target HR = resting + % × (max − resting)The five zones
| Zone | Name | % of max HR | What it is for |
|---|---|---|---|
| 1 | Recovery | 50–60% | Warm-up, cooldown, active recovery |
| 2 | Endurance | 60–70% | Easy miles — the base ~80% of training |
| 3 | Tempo | 70–80% | Steady, comfortably hard work |
| 4 | Threshold | 80–90% | Intervals, lactate-threshold work |
| 5 | Maximum | 90–100% | Sprints and VO₂max, seconds to minutes |
Frequently asked questions
Is 220 minus age accurate?
Not really — it overestimates young hearts and underestimates older ones, with a ±12 bpm standard deviation. The Tanaka formula (208 − 0.7 × age) fits lab data better, which is why we use it.
Which column should I train by?
Karvonen (heart-rate reserve) if you know your resting heart rate — it lines up with perceived effort. % of max is fine for a rough guide or when comparing with chart-based training plans.
How do I measure my resting heart rate?
Right after waking, before getting up or caffeine: count your pulse for 60 seconds, or wear an overnight tracker and read the sleep-average. A few mornings' average is better than one.
My watch shows different zones — who is right?
Watches often guess zones from 220 − age or auto-calibrate from runs. Use whichever method you pick consistently; the Karvonen numbers here are the defensible baseline.