Heart Rate Zones Calculator
Calculate your 5 training zones with the Karvonen or % max HR method
Measure on waking, lying down. Enables the Karvonen method.
Overrides the formula if you know your actual max HR.
Your Training Heart Rate Zones
Karvonen method (heart rate reserve) — more accurate when resting HR is known
These calculations are estimates based on widely used formulas. Consult a healthcare professional before starting an intensive training programme. Max HR formulas may vary by ±10–15 bpm between individuals.
How to use the Heart Rate Zones Calculator
Enter your age or max HR
Type your age and the calculator estimates your maximum heart rate. If you know your exact max HR from a lab test, enter it directly to override the formula.
Choose a formula
Pick Tanaka (recommended), Haskell-Fox (classic 220 − age), or Gellish. Optionally add your resting HR to enable the more precise Karvonen method.
Read your 5 zones
Your zones appear instantly. Each zone shows its BPM range, training purpose, and intensity level so you can plan your sessions with precision.
Why train with heart rate zones?
Heart rate zone training lets you target specific physiological adaptations. Low zones (Z1–Z2) build aerobic base and running economy without excessive fatigue. High zones (Z4–Z5) raise lactate threshold and VO2max. Polarised training — 80% in Z1–Z2 and 20% in Z4–Z5 — is the method favoured by elites and supported by research.
Heart rate formulas explained
The classic 220 − age (Haskell-Fox, 1971) is the best-known formula, but it carries a high standard deviation of ±10–12 bpm. Modern formulas by Tanaka (2001) and Gellish (2007) are more accurate for active adults, having been validated on large cohorts. If you know your actual max HR from a maximal exercise test, enter it directly for more reliable zones.
Tanaka (2001)
208 − 0.7 × age
Recommended — validated on 514 subjects, accurate for adults aged 20–90
Haskell-Fox (1971)
220 − age
Classic — easy to remember, ±12 bpm standard deviation
Gellish (2007)
207 − 0.7 × age
Modern — similar to Tanaka, slightly different for older adults
Frequently asked questions
The most accurate method is a supervised maximal exercise test. For everyday use, the Tanaka formula (208 − 0.7 × age) and Haskell-Fox (220 − age) give good estimates. Tanaka is recommended for active adults as it was validated on a large cohort.
Zone 2 (60–70% max HR) is the optimal fat-burning zone. At this intensity your body primarily uses fat as fuel. Long Z2 sessions (60–90 minutes) maximise fat oxidation while limiting fatigue.
The Karvonen method (also called heart rate reserve or HRR) is more accurate than simple % max HR because it accounts for your resting HR. Formula: target HR = resting HR + (% intensity × (max HR − resting HR)). A well-trained runner with a low resting HR will have different absolute zones than a beginner, even at the same max HR.
A recovery jog sits in Zone 1 (50–60% max HR). A base endurance run sits in Zone 2 (60–70% max HR). You should be able to hold a full conversation in Z1–Z2. If you are breathless, slow down — you have drifted into Z3 or higher.
Zone 4 (lactate threshold) is typically trained in 10–20 minute intervals or 2–6 km repeats. Zone 5 (VO2max) is trained with short 30-second to 4-minute efforts. Polarised training recommends limiting Z4–Z5 volume to 10–20% of total weekly training load.