Heart Rate Zones Calculator
Free heart rate training zone calculator. Get Karvonen or max-HR percentage zones by age and resting heart rate. Zone 1-5 ranges. No signup.
Training zones from your age and resting heart rate
This calculator converts your age and resting heart rate into five training zones in beats per minute, and shows your estimated maximum heart rate, resting rate, and heart-rate reserve. Two methods are offered: Karvonen, which uses heart-rate reserve, and the simpler percentage-of-maximum method.
How the formulas work
Max heart rate defaults to 220 − age unless you type a measured value into the optional field. The calculator then finds your heart-rate reserve:
Heart-rate reserve = max HR − resting HR
Each of the five zones is a percentage band. The method you select changes only the formula used to turn a percentage into a heart rate:
- Karvonen: bpm = resting HR + (reserve × zone %)
- Max HR percentage: bpm = max HR × zone %
Karvonen is the default, and it is the more personal of the two because it starts from your resting rate. A lower resting heart rate means a larger reserve, which pushes every band higher. If your resting rate is ever entered above your max, the calculator lowers it to one beat below max so the math still works.
Worked example with the default inputs
The tool opens with age 30, resting heart rate 60 bpm, and the Karvonen method. Step by step:
- Max HR = 220 − 30 = 190 bpm
- Reserve = 190 − 60 = 130 bpm
- Zone 2 low = 60 + (0.60 × 130) = 60 + 78 = 138 bpm
- Zone 2 high = 60 + (0.70 × 130) = 60 + 91 = 151 bpm
| Zone | Reserve % | Heart rate | Purpose |
|---|---|---|---|
| 1 — Recovery | 50–60% | 125–138 bpm | Warm-up and easy movement |
| 2 — Endurance | 60–70% | 138–151 bpm | Sustainable aerobic base |
| 3 — Tempo | 70–80% | 151–164 bpm | Comfortably hard aerobic work |
| 4 — Threshold | 80–90% | 164–177 bpm | Lactate threshold, race pace |
| 5 — VO2 max | 90–100% | 177–190 bpm | Short maximal efforts |
Switch the method to max HR percentage and Zone 2 becomes 114–133 bpm (190 × 0.60 to 190 × 0.70). The bands sit lower because that method ignores how low your resting rate is.
How to use the zones
Most weekly volume belongs in Zones 1 and 2. Zone 3 is useful for steady tempo sessions, while Zones 4 and 5 should be rationed to one or two hard sessions a week. If every session feels hard, recovery stalls and progress reverses. Re-measure resting heart rate on waking, before getting out of bed, for a consistent reading.
Common mistakes
- Treating 220 − age as exact. It is a population average; a true max HR can differ by 10–15 beats.
- Mixing the two methods. Choose one and stay with it so your zones remain comparable week to week.
- Racing every session. Living in Zones 4 and 5 produces fatigue rather than fitness.
- Using a stale resting rate. Update it every few weeks; a five-beat drop rearranges all five zones.
Can I use these zones without a chest strap?
For steady Zone 2 work, a wrist optical sensor is close enough. It lags during rapid changes, so intervals read poorly on a wrist device; a chest strap tracks fast shifts better.
Why are my zones different from my watch’s?
Most watches use either max-HR percentage or a proprietary variant. If yours is based on a measured max HR from a field test, its bands will sit higher or lower than the 220 − age estimate here. Enter that measured value in the optional max HR field to match it.
Does sex change the max heart rate formula?
The classic 220 − age formula ignores sex. Some coaches use 226 − age for women, but the individual spread is wider than the sex difference, so a measured max HR beats any formula.
How do I find my true max heart rate?
A field test gives a closer estimate than a formula. A common protocol is a thorough warm-up, then three minutes hard, three minutes easy, three minutes harder, and a final one-minute sprint, taking the highest reading on a chest strap. Because the effort is maximal, do it when rested, and clear it with a doctor first if you have cardiac risk factors.
These zones are an estimate, not medical advice. If you have a heart condition or take medication that affects heart rate, confirm target ranges with a clinician. To match zones to energy needs, pair them with the TDEE calculator, and to turn that target into a fuel plan, the macro calculator. For pace rather than heart rate, the running pace calculator uses the same effort scale.