How to use the Heart Rate Zones
- Enter your maximum heart rate, measured if possible or estimated from age.
- Enter your resting heart rate for the more accurate Karvonen zones.
- Read the five zone ranges in beats per minute.
- Spend most easy training in zones 1 and 2 rather than drifting into zone 3.
How the calculation works
Zone 1 sits at 50 to 60% of maximum for recovery, zone 2 at 60 to 70% for aerobic base building, zone 3 at 70 to 80% as tempo, zone 4 at 80 to 90% at threshold, and zone 5 above 90% for VO2 max work. The Karvonen method applies those percentages to heart rate reserve — maximum minus resting — and adds resting back, which raises the targets for people with low resting rates and better reflects actual effort.
Age-predicted maximum is the weak link. The 220-minus-age estimate carries a standard deviation of 10 to 12 beats, so an individual's true maximum can differ by twenty beats in either direction; Tanaka's 208 − 0.7 × age performs better across age groups. A field test or lab measurement is far more useful. Most endurance research supports polarised training — around 80% of volume easy in zones 1 and 2, the rest hard — with the common failure being sessions that drift into zone 3, too hard to recover from and too easy to drive adaptation.
Simple: zone = %HRmax ; Karvonen: target = ((HRmax − HRrest) × %) + HRrest ; Tanaka HRmax = 208 − 0.7 × ageSource: Karvonen heart rate reserve method; Tanaka et al. (2001) maximum heart rate prediction; polarised training distribution per Seiler's endurance research.
Worked example
A 41-year-old with a resting heart rate of 52, using Tanaka for maximum.
- HRmax = 208 − 0.7 × 41 = 179.
- Reserve = 179 − 52 = 127.
- Zone 2 (60–70%): 52 + 127×0.6 = 128 to 52 + 127×0.7 = 141.
- Zone 4 (80–90%): 154 to 166.
Easy aerobic work sits at 128 to 141 bpm and threshold work at 154 to 166 — noticeably higher than the simple percentage method would suggest.
Frequently asked questions
How accurate is 220 minus age?+
Poorly for individuals — the standard deviation is 10 to 12 beats. Tanaka's 208 − 0.7 × age is better, and a measured maximum from a field test is better still.
Should I use Karvonen or simple percentages?+
Karvonen, if you know your resting heart rate. It accounts for fitness and gives targets that better match perceived effort, particularly for well-trained athletes.
Why should most training be easy?+
Polarised training — roughly 80% easy, 20% hard — produces better endurance adaptation than constant moderate work, which accumulates fatigue without delivering a strong stimulus.
Why is my heart rate higher than usual today?+
Heat, dehydration, caffeine, poor sleep, illness and stress all raise it for a given effort. On those days, run by effort rather than chasing a zone number.
Last reviewed August 31, 2026. We review this page whenever the underlying formula, tax year, published rate or standard changes.