Zone 2 Heart Rate Calculator.
Zone 2 training is the single highest-leverage protocol for metabolic health and longevity. Find your exact BPM range and all 5 training zones.
Frequently Asked Questions
What is my Zone 2 heart rate range?+
Zone 2 is the heart-rate band where you train your aerobic base — roughly 60–70% of your heart-rate reserve. This calculator computes your personal range from your age and resting heart rate using the Karvonen formula, so it accounts for fitness, not just a generic "220 minus age" estimate.
Is Zone 2 the same as the fat-burning zone?+
Largely, yes. Zone 2 is the intensity at which your body relies most on fat for fuel, because it is below the threshold where lactate starts accumulating. It is the same easy, conversational effort marketed on cardio machines as the "fat-burning zone" — but the value here is dialed to your own heart rate rather than a one-size chart.
How do I find my Zone 2 with a heart-rate or cardio calculator?+
Enter your age and resting heart rate above and the tool returns your Zone 2 bpm range. As a field check, Zone 2 is the hardest effort at which you can still hold a full conversation — if you are gasping between words, you have drifted into Zone 3.
How much Zone 2 cardio should I do per week?+
Peter Attia and much of the longevity literature point to about 150–180 minutes per week, typically spread across three to four sessions of 45–60 minutes. The volume matters more than intensity here — staying genuinely in Zone 2 is what builds mitochondrial density and metabolic flexibility.
How do I calculate Zone 2 heart rate?+
Two common methods, both in this calculator. The simple way: Zone 2 ≈ 60–70% of your maximum heart rate, where max HR ≈ 220 − age. The more accurate way is the Karvonen (heart-rate reserve) formula: Zone 2 = resting HR + 0.6–0.7 × (max HR − resting HR), which adapts the range to your fitness. Enter your age (and resting heart rate for Karvonen) and the tool returns your exact zone-two bpm range.
What is a good Zone 2 heart rate range by age?+
Because the range is anchored to 220 − age, it drifts down as you get older. Rough Max-HR-% ballparks: around 117–137 bpm at age 30, 111–130 at 40, 105–122 at 50, and 99–115 at 60. These are estimates — use the Karvonen method with your resting heart rate for a range tuned to you rather than a generic zone-2 chart.
What Zone 2 actually is.
Zone 2 is the intensity at which your body produces energy almost entirely through aerobic, fat-burning pathways with minimal lactate accumulation. In physiology terms, it sits at the first lactate threshold — the highest intensity you can sustain while blood lactate stays under ~2 mmol/L. In practical terms: you can hold a conversation in full sentences, but it would be uncomfortable to do for long.
In heart rate terms, Zone 2 typically falls at 60–70% of maximum heart rate, or 70–80% of heart rate reserve using the Karvonen formula. This calculator uses the more accurate Karvonen method when you provide a resting heart rate.
Why longevity researchers care.
Sustained Zone 2 training drives mitochondrial biogenesis — your cells build more and better mitochondria, the organelles that convert fuel into ATP. Metabolic flexibility (the ability to switch efficiently between burning fat and glucose) is one of the strongest predictors of cardiovascular and metabolic health. Zone 2 is the single training modality with the most direct effect on it.
Most longevity-focused training prescriptions converge on 150–180 minutes of Zone 2 per week, split across 3–4 sessions of 45–60 minutes. Add one weekly VO2 max session (4–5x 4-min near-max intervals) for the cardiorespiratory ceiling.
How to know you are actually in Zone 2.
The talk test is the field-standard check: speak a full sentence comfortably; if you cannot, you are above Zone 2. Nose breathing is another rough proxy — if you can sustain it, you are likely in zone. A lactate meter ($150–$300) gives a precise reading; 1.5–2.0 mmol/L blood lactate is canonical Zone 2.
The most common mistake is going too hard. Heart rate drift, ego, and fatigue make Zone 2 feel "too easy" — which is the point. Iñigo San-Millán's widely-cited prescription: if you have to ask whether you are in Zone 2, you are above it. Slow down.
- San-Millán I, Brooks GA. (2018). Assessment of metabolic flexibility by means of measuring blood lactate, fat, and carbohydrate oxidation responses to exercise in professional endurance athletes. Sports Med, 48(2), 467–479.
- Holloszy JO, Coyle EF. (1984). Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. J Appl Physiol, 56(4), 831–838.
- Karvonen MJ, Kentala E, Mustala O. (1957). The effects of training on heart rate; a longitudinal study. Ann Med Exp Biol Fenn, 35(3), 307–315.
Zone 2 only compounds if you actually log it. Track every base session and weekly lift in one planner.
Get the guide →For education, not medical advice. Results are estimates, not a diagnosis — discuss any abnormal value or health concern with a qualified clinician.
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