Training · Free tool
Heart Rate Training Zones Calculator
Enter your age for a quick estimate, or add your measured maximum and resting heart rate for personalised zones using the Karvonen method. We return all five training zones in beats per minute.
What the five zones mean
Zone 1 (recovery) and Zone 2 (easy/aerobic) build your aerobic base and should make up the bulk of most runners’ weekly volume. Zone 3 (tempo) is the “comfortably hard” middle ground. Zone 4 (threshold) sits at the edge of what you can sustain, and Zone 5 (VO₂ max) is the short, sharp end reserved for intervals.
The popular 80/20 approach puts roughly 80% of training time in Zones 1–2 and 20% in Zones 3–5. Most amateur runners spend too long in Zone 3 — fast enough to tire them, not fast enough to drive adaptation.
Max-HR estimate vs. Karvonen
With only your age, we estimate maximum heart rate as 208 − 0.7 × age (the Tanaka formula, more accurate than the old 220 − age rule) and take zones as a percentage of that. Add your resting heart rate and we switch to the Karvonen heart-rate-reserve method, which anchors the zones to your individual fitness and is meaningfully more precise.
For the most accurate zones of all, replace the age estimate with a maximum heart rate you have actually seen on a hard hill-rep or race finish.
Frequently asked questions
Is 220 minus age accurate?
It is a rough population average with a wide error margin — easily ±10–12 bpm for an individual. We use the Tanaka formula (208 − 0.7 × age) instead, and recommend a measured max where possible.
What is the Karvonen formula?
Karvonen calculates zones from your heart-rate reserve (max minus resting): target = resting + reserve × intensity%. Because it accounts for resting heart rate, it personalises the zones to your fitness rather than assuming an average.