Heart Rate Zones Calculator
Find your 5 training zones for optimal running and cardio
Measure your pulse first thing in the morning before getting up. Leave blank to use age-based calculation only.
Maximum Heart Rate (MHR)
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bpm — formula: 220 − age
Zone 1 — Recovery
50–60% MHR · Easy walk · Active recovery
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Zone 2 — Base / Fat burn
60–70% MHR · Conversational pace · Long runs
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Zone 3 — Aerobic
70–80% MHR · Moderate effort · Tempo runs
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Zone 4 — Threshold
80–90% MHR · Hard effort · 10K race pace
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Zone 5 — Maximum
90–100% MHR · All-out sprint · Short intervals
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Understanding Heart Rate Zones
Why train in different zones?
Each zone targets different energy systems and fitness adaptations. Zone 2 builds aerobic base and burns fat. Zone 4 improves lactate threshold. Zone 5 builds speed and VO2 max. Most training plans recommend 80% easy (Zone 1–2) and 20% hard (Zone 4–5).
How accurate is 220 − age?
The 220 − age formula is a rough estimate. Individual maximum heart rates can vary by ±10–20 bpm. For the most accurate MHR, do a supervised max-effort test or use a fitness test protocol.
What is Karvonen method?
The Karvonen (Heart Rate Reserve) method uses your resting heart rate to calculate zones more precisely: Target HR = Resting HR + (MHR − Resting HR) × Zone %. This is more accurate for individuals with high or low resting heart rates.