Work out your five training heart-rate zones in bpm from your age, sex and resting heart rate, and see how much time to spend in each one.
Advanced: max heart rate method and zone model
| Zone | Purpose | Heart rate |
|---|---|---|
| Z1 Recovery | Very easy effort that aids recovery and warm-up; you can talk freely. | - |
| Z2 Endurance | Steady aerobic base building and fat use; conversational pace for long sessions. | - |
| Z3 Tempo | Moderately hard; improves aerobic efficiency but talking gets harder. | - |
| Z4 Threshold | Hard effort near lactate threshold; raises the pace you can hold for long. | - |
| Z5 Maximum | Near all-out intervals; builds top-end power and oxygen uptake in short bursts. | - |
For beginners: how to read these zones
To get your zones, pick a starting preset or enter your own values: sex, age and resting heart rate. Measure resting heart rate in the morning before getting up for the most reliable figure. The advanced section lets you choose how maximum heart rate is estimated and which zone model is used.
How maximum heart rate is estimated
Your zones are derived from a maximum heart rate, and several formulas exist.
- Fox (default): maximum heart rate equals 220 minus age in years. Simple and widely known, but less accurate at the extremes of age.
- Tanaka: maximum heart rate equals 208 minus 0.7 times age. It fits a broad age range better than the Fox formula.
- Gulati: maximum heart rate equals 206 minus 0.88 times age, derived specifically from data on women.
- Measured: enter the highest heart rate recorded in a maximal effort test. A real test beats any formula.
Two zone models
The percent of maximum heart rate model multiplies your maximum by each zone percentage. The Karvonen model works from heart-rate reserve, which is maximum heart rate minus resting heart rate; each zone is resting heart rate plus a percentage of that reserve. Because Karvonen uses your resting rate, it shifts the zones toward your own fitness level, and a fitter heart with a lower resting rate widens the reserve.
The five zones
Zone borders are set at 50-60, 60-70, 70-80, 80-90 and 90-100 percent. Zone 1 is recovery, Zone 2 is the aerobic endurance and fat-use base, Zone 3 is tempo, Zone 4 is threshold work near the lactate threshold, and Zone 5 is near-maximal intervals. The polarised 80/20 split keeps roughly 80 percent of weekly training time easy in Zones 1-2, a small share moderate in Zone 3, and the rest hard in Zones 4-5.
What is not included
Age-based maximum heart rate formulas can be off by 10-12 bpm for one person. The calculator does not account for medication that affects heart rate, heart conditions, altitude, heat, illness or caffeine. It is an estimate for healthy training planning, not a medical or diagnostic tool.