Zone 2 Calculator — Easy Aerobic Heart Rate
Calculate your Zone 2 heart rate (Karvonen or Tanaka) for easy runs, long runs and aerobic base building.
What is Zone 2 and how do I know I'm in it?
Zone 2 is low-intensity aerobic training — typically 60–70% of max HR — where you can still hold a conversation. It builds mitochondria, improves fat oxidation and creates the base that supports long races. Elites often spend 70–80% of volume here. This page is the tool to find your bpm range; for the full Z1–Z5 map, use the heart rate zones guide.
- Talk test: you can speak full sentences comfortably
- Rate of perceived exertion (RPE 3–4 on a 1–10 scale)
- Comfortable breathing, no shortness of breath
How much time in Zone 2 per week?
Guideline weekly aerobic volume:
| Goal | Weekly time |
|---|---|
| Health | 75–150 min |
| 5K | 1–2 h |
| Half marathon | 2–4 h |
| Marathon | 3–6 h |
Why it matters and common mistakes
Zone 2 matters because it is the building block of sustainable volume: better economy without excessive fatigue. Common mistakes: running too fast (slipping into gray-zone 3), ignoring HR drift on hot long runs, and comparing your HR to other runners. Enter resting HR when possible (Karvonen) for a more personalized range.
Zone 2 by age (reference)
| Age | Max HR | Zone 2 |
|---|---|---|
| 20 | 194 | 116–136 |
| 25 | 191 | 115–134 |
| 30 | 187 | 112–131 |
| 35 | 184 | 110–129 |
| 40 | 180 | 108–126 |
| 45 | 177 | 106–124 |
| 50 | 173 | 104–121 |
| 55 | 170 | 102–119 |
| 60 | 166 | 100–116 |
| 65 | 163 | 98–114 |
Frequently asked questions about Zone 2
Build your weekly Zone 2 training automatically
Let Rai create aerobic workouts tailored to your fitness.