Running Heart Rate Zones Calculator
Calculate your 5 training heart rate zones using the Karvonen formula.
Enter max and resting heart rate for personalized zones.
How Running Pace Relates to Heart Rate
Running pace and heart rate are correlated through aerobic effort, but the relationship is individual. The key is finding what heart rate corresponds to your target training pace.
Effort-Based Pace Zones:
Using Heart Rate Reserve (HRR) method (Karvonen formula):
Target HR = Resting HR + (HRR × Intensity%)
Where: HRR = Max HR − Resting HR
Worked Example: Runner: age 32, resting HR = 55 bpm, Max HR = 188 bpm
- HRR = 188 − 55 = 133 bpm
Easy run (Zone 2, 60–70% HRR):
- Lower = 55 + (133 × 0.60) = 55 + 79.8 = 135 bpm
- Upper = 55 + (133 × 0.70) = 55 + 93.1 = 148 bpm
Typical Pace-to-Zone Mapping (well-trained runner):
| Zone | HR Range | Pace (5km racer at 22 min) |
|---|---|---|
| 1 | 120–135 bpm | >6:00/km (very easy) |
| 2 | 135–148 bpm | 5:30–6:00/km (easy) |
| 3 | 148–162 bpm | 5:00–5:30/km (moderate) |
| 4 | 162–175 bpm | 4:30–5:00/km (hard) |
| 5 | 175+ bpm | <4:30/km (max effort) |
Cardiac Drift: On long runs, heart rate gradually rises even at constant pace — dehydration and heat increase HR by 5–15 bpm over 60–90 minutes. Slow down to maintain target zone, not target pace.
GPS Watch Integration: Modern watches calculate this automatically using chest strap or optical HR plus pace data.