Zone 2 Heart Rate Calculator
The easy-aerobic zone 2 band (60–70% intensity) from your age — and, when you add a resting heart rate, the Karvonen heart-rate-reserve version alongside it. For the full 50–85% zone ladder, see the Target Heart Rate Calculator; for pacing runs by speed instead, the Pace Calculator.
Your zone 2 band
Example: age 30 → 114–133 bpm (% of max); with resting 60 → 138–151 bpm (Karvonen).
Two methods, deliberately side by side
At age 30 the age-predicted maximum is 190 bpm (220 − age), and 60–70% of it is 114–133 bpm. With a resting rate of 60, the Karvonen formula — (max − rest) × intensity + rest — puts the same percentages at 138–151 bpm. Both examples are computed by the same tested engine as the calculator. The gap is not an error: percent-of-max measures from zero, Karvonen from your resting rate, so the reserve-based band sits higher. Devices and coaches use both conventions, which is exactly why this page refuses to average them into one number.
Which band should you trust?
Neither formula knows your physiology. 220 − age carries a spread of ±10–15 bpm in adults and is least reliable for teens, whose measured maximums often sit below the convention. If your easy efforts at the computed band feel like a conversation-pace jog, the number is serving its purpose; if you are straining or bored, trust perceived effort and the talk test over the arithmetic. A lab or field test for your first lactate threshold is the genuinely personal answer.
Frequently asked questions
What is zone 2, exactly?
In the common five-zone model, zone 2 is easy aerobic effort — commonly framed as 60–70% intensity, a pace where conversation stays comfortable. Physiologically the term is often used for effort below the first lactate threshold, which is personal and found by testing, not by formula.
Why do the two methods give different numbers?
Percent-of-max takes 60–70% of the estimated maximum directly. Karvonen takes 60–70% of the heart-rate reserve — the gap between resting and maximum — and adds the resting rate back, so its band sits higher for the same percentages. Neither is "wrong"; they are different conventions, which is why both are shown.
How reliable is 220 − age?
It is a population average with a wide individual spread — being 10–15 bpm off is common. It was also characterized in adults, so it is least reliable for teenagers, whose measured maximums often differ from the formula by 10 or more bpm. A measured maximum beats the estimate whenever you have one.
What is zone 2 training commonly used for?
Endurance practice commonly places large volumes of easy aerobic work in zone 2 to build the aerobic base while keeping recovery cost low. This page describes that usage; it does not prescribe a training plan — how much time you should spend at any intensity depends on your goals and health.
Can I just use the talk test instead?
Yes — "can hold a conversation, but knows they are exercising" is a serviceable proxy for easy aerobic effort and needs no arithmetic. Heart-rate bands are most useful when you want a number to hold steady on a device.
Not medical advice: formula-based heart-rate bands are population estimates and can be misleading for individuals — particularly with cardiac conditions or heart-rate-affecting medication such as beta blockers. Consult a qualified healthcare professional before intensity-based training. Data is processed locally in your browser and never transmitted. See the methodology page.