Heart Rate Zone Calculator
Calculate your five training zones from maximum and resting heart rate using the Karvonen method.
Your details
Measured first thing in the morning
Leave at 0 to estimate from age
Method
This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works
Maximum heart rate
184 bpm
Heart rate reserve 126 bpm · resting 58 bpm
Includes your inputs, the full breakdown, and every row of the table.
Zone 2 (aerobic base)
134–146 bpm
Easy endurance. The bulk of weekly volume for most athletes.
Threshold (Zone 4)
159–172 bpm
Heart rate reserve
126 bpm
Method
Karvonen
| Zone | Intensity | Heart rate | Purpose |
|---|---|---|---|
| Zone 1 — Recovery | 50%–60% | 121–134 bpm | Very easy, conversational. Warm-up and active recovery. |
| Zone 2 — Aerobic base | 60%–70% | 134–146 bpm | Easy endurance. The bulk of weekly volume for most athletes. |
| Zone 3 — Tempo | 70%–80% | 146–159 bpm | Comfortably hard. Improves aerobic capacity and lactate clearance. |
| Zone 4 — Threshold | 80%–90% | 159–172 bpm | Hard. Around lactate threshold; sustainable for roughly an hour. |
| Zone 5 — VO₂ max | 90%–100% | 172–184 bpm | Maximal. Short intervals only. |
What this means
- The Karvonen method uses heart rate reserve — the gap between resting and maximum — which personalises zones far better than a flat percentage of max heart rate.
- Age-based formulas carry a standard deviation of roughly 10-12 beats per minute. A field test or a race effort gives a much better max than any equation.
How the heart rate zone calculation works
Heart rate zones translate effort into a number you can hold yourself to. The five-zone model splits the range between easy recovery and maximal effort, with each zone driving different physiological adaptations — mitochondrial density and fat oxidation at the low end, lactate tolerance and VO₂ max at the top.
The Karvonen method anchors zones to heart rate reserve rather than maximum alone. Two people with the same max heart rate but resting rates of 45 and 70 have very different working ranges, and Karvonen accounts for that.
Frequently asked questions
What is Zone 2 training?
Easy aerobic work at roughly 60-70% of heart rate reserve — a pace where you can hold a conversation. It builds the aerobic base that supports everything above it, and most endurance programmes spend 70-80% of total time there.
How accurate is 220 minus age?
Poorly. It systematically overestimates max heart rate in younger adults and underestimates it in older ones. Tanaka's 208 − 0.7 × age fits population data better, but individual variation of ±10 bpm remains.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.