Enter your age and resting heart rate to get all five training zones by the Karvonen method — including the Zone 2 range everyone is asking about.
Why zones — and why Karvonen
Training zones turn “run easier” into a number on your watch. The simple method takes percentages of your estimated max (220 minus age); the Karvonen method this calculator uses is a step better, because it works from your heart rate reserve — the span between resting and max — so two people of the same age with different fitness get different, more personal zones.
How to use it
- Enter your age.
- Enter your resting heart rate — measured on waking is best.
- Read all five zones; most endurance training lives in Zone 2.
The formula
A worked example
A 30-year-old with a resting rate of 60: estimated max 190 bpm, reserve 130, and the famous Zone 2 lands at 138–151 bpm — the conversational pace where long-run endurance is built. Zone 4 threshold work sits at 164–177, and Zone 5 is the short-interval ceiling above that.
An honest caveat
220-minus-age is a population estimate with a spread of ±10 or more beats — a lab test or a hard-effort field test pins your real max better. Treat these zones as a solid starting point, not a prescription; and anyone with a heart condition or on rate-affecting medication should get zones from their doctor, not a formula.