Heart Rate Zone Calculator
Use this tool to calculate your training zones for running, cycling, rowing, or cardio sessions. You can use a simple % of max heart rate method or the Karvonen (heart rate reserve) method.
If blank, max heart rate is estimated as 220 − age.
Good for a quick estimate if you do not track resting heart rate regularly.
Why heart rate zones matter
Training by heart rate helps you match workout intensity to a clear physiological target. Instead of guessing whether a run is easy, moderate, or hard, your monitor gives objective feedback in beats per minute (bpm). This makes your training more efficient and helps reduce overtraining.
Heart rate zones are usually split into five levels, from easy recovery work (Zone 1) to near-maximal effort (Zone 5). Most people make the best long-term progress by spending most of their time in lower zones and using high zones strategically.
How to calculate heart rate zones
1) Estimate or measure max heart rate
The quick estimate is 220 − age. For example, at age 35, estimated max HR is 185 bpm. This is convenient, but not perfect. If you know your tested max heart rate from a lab test or hard field test, use that value for better accuracy.
2) Choose your method
- % Max HR method: Uses percentages of max heart rate only.
- Karvonen (HRR) method: Uses max heart rate and resting heart rate. This often personalizes zones better, especially if your resting HR is unusually low or high.
3) Apply standard zone ranges
A common 5-zone model uses these ranges:
- Zone 1: 50–60%
- Zone 2: 60–70%
- Zone 3: 70–80%
- Zone 4: 80–90%
- Zone 5: 90–100%
What each zone is used for
Zone 1 (Very easy)
Great for warm-ups, cool-downs, and active recovery days. Conversation should feel effortless.
Zone 2 (Easy aerobic)
Builds aerobic base, improves endurance, and supports fat oxidation. This is the backbone of most sustainable training plans.
Zone 3 (Moderate tempo)
Useful for steady-state efforts and improving your ability to maintain a stronger pace. Harder to talk continuously, but still controlled.
Zone 4 (Threshold)
Improves lactate threshold and performance at race pace. Feels hard and requires focus; usually done in intervals or structured blocks.
Zone 5 (VO2 max / very hard)
Short, high-intensity efforts to improve top-end aerobic power and speed. Limited volume, lots of recovery.
Example
If you are 40 years old, your estimated max HR is 180 bpm. Using the % Max method, Zone 2 is about 108–126 bpm (60–70% of 180). If your resting HR is 60 and you use Karvonen, the same Zone 2 will often shift slightly and may fit your body better.
Practical tips for better accuracy
- Measure resting heart rate right after waking up, before coffee or movement.
- Use a chest strap for harder workouts; wrist sensors can lag during intervals.
- Recalculate zones every few months as fitness changes.
- Use zones as guidance, not rigid rules—sleep, stress, heat, and hydration all affect heart rate.
Common mistakes to avoid
- Doing every session in Zone 3–4 and never truly training easy.
- Using outdated max HR values for years.
- Ignoring recovery signals because the watch says you are “in zone.”
- Comparing your heart rate numbers directly with someone else’s.
Final note
This calculator is educational and helpful for training planning, but it is not medical advice. If you have cardiovascular conditions, symptoms during exercise, or are new to intense training, consult a qualified healthcare professional before starting a hard program.