Find the easy aerobic range where longevity is built - the pace you can hold a conversation at. Works with or without your resting heart rate.
| Zone | Effort | Range (bpm) |
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Ranges are estimates. The most reliable field check for Zone 2 is the talk test: you can hold a conversation but not comfortably sing.
Haptic alerts on your Garmin buzz you back into the zone - so you run by feel, eyes up, and let the watch do the correcting.
Get DaInterval ProZone 2 is the top of your easy aerobic range - hard enough to drive adaptation, easy enough to sustain for an hour and still talk. It's where you build mitochondrial density, fat-burning capacity, and a durable cardiovascular base with minimal joint strain and low injury risk. That low-strain quality is exactly why it matters more with age: most of your training volume should be easy enough that you can keep doing it for decades. A 2025 international expert consensus formalized how Zone 2 should be defined for training and research (Int'l Journal of Sports Physiology & Performance, PMID 40010355). The anti-hustle takeaway: go easy most of the time, stay consistent, and let the aerobic base compound.
Percentage of max HR (default): When you enter only your age, we estimate maximum heart rate with the classic 220 − age formula and take Zone 2 as roughly 60–70% of that. This is a convenient starting point, but it carries wide individual variation - real max HR can be 10–20 bpm off the estimate - so treat the output as a rough guide, not a measurement.
Karvonen / heart-rate reserve (when you add resting HR): If you enter your resting heart rate, we switch to the Karvonen method, which calculates zones from your heart-rate reserve (max HR − resting HR) and adds resting HR back in. This personalizes the range to your fitness and is generally more accurate than a flat percentage of max. Entering a lab- or field-tested max HR override improves accuracy further.
Zone 2 is commonly placed at roughly 60–70% of maximum heart rate, though exact boundaries vary by model and individual. When resting heart rate is available, the Karvonen (heart-rate reserve) method gives a more personalized range than a flat percentage. Because estimated max HR itself can be off by 10–20 bpm, no formula is exact - use the calculator's number as a starting range and confirm with the talk test: in Zone 2 you can converse but not sing. Over several runs your perceived effort becomes a more trustworthy guide than any single number.
It's convenient but imprecise. The 220 − age formula is a population average with substantial individual scatter - your true max heart rate could sit well above or below the estimate. It's fine as a starting point when you have no better data, but if you want accuracy, a proper max-HR test (or a lab assessment) and entering that value as an override will meaningfully sharpen your zones. For most people building an easy aerobic base, the estimate paired with the talk test is good enough to train by.
Because it switches the math to the Karvonen method, which bases zones on your heart-rate reserve - the gap between your resting and maximum heart rate - rather than a flat percentage of max. A fitter person with a low resting HR has a wider reserve, so their zones shift accordingly. Karvonen personalizes the range to your cardiovascular fitness and is generally regarded as more accurate for training zones than the simple percentage-of-max approach, which is why the calculator prefers it whenever you supply a resting HR.
The talk test is the most practical check: in Zone 2 you can speak in full sentences but couldn't comfortably sing. Breathing is elevated but controlled, and the effort feels almost too easy - that's normal and correct. Many people run their "easy" days too hard, which is exactly the trap Zone 2 training avoids. If your heart-rate monitor says you're in range but you're gasping, trust your body and ease off; if it says you're below range but you're conversational and steady, you're likely fine. Effort and heart rate should agree over time.
General guidance for building an aerobic base is that the majority of your weekly training volume should be easy, with a smaller portion at higher intensities. Many endurance approaches put roughly 80% of sessions in easy/Zone 2 territory. The exact split depends on your goals, history, and recovery, but the principle is consistent: most of your work should feel sustainable, not punishing. For people 40+ prioritizing longevity over performance, leaning even more toward easy volume - and staying consistent - usually beats chasing hard sessions you can't recover from.
A watch's optical wrist sensor is enough to get started and works fine for steady, easy running. Chest straps are generally more accurate and more responsive, especially during pace changes, so if you want tight zone control they're a worthwhile upgrade. For guiding Zone 2 specifically, the bigger win isn't sensor precision - it's not having to look at the number at all. An app like DaInterval Pro uses haptic alerts to buzz you back into range, so you can run by feel with either a wrist sensor or a chest strap.
This calculator provides general estimates for educational purposes and is not medical advice. Heart-rate formulas carry significant individual variation. Consult a qualified healthcare professional before starting a new exercise program, especially if you have a cardiovascular condition, take heart-rate-affecting medication, or are new to training.