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- Heart Rate Zone Calculator: Find Your Zone 2 and All Five Zones
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Heart Rate Zone Calculator: Find Your Zone 2 and All Five Zones
This heart rate zone calculator gives you an estimated maximum heart rate and five training zones in beats per minute, including your zone 2 range for easy aerobic work. Add your resting heart rate for more personal zones.
Journals that use this number
Every number calculated by code from published formulas.
- Couch to 5K running planfrom €15Tell us how much you can run today, your 5 km goal, how often you can run and anything that needs care. Your journal sets the starting week and the pace of progression for you, then gives you a tick-off page for every run.
- Walking plan for weight lossfrom €15Enter your current steps, height, weight, age, goal and how long you can walk. Your journal sets a weekly step ramp, picks interval or incline sessions to suit your knees and kit, and estimates the distance and energy behind every target.
- HYROX training planfrom €24Enter your race date, your 5 km time, how many days you can train and what equipment you have. Your journal counts back from race day and prints every session with your own paces, station work and equipment swaps.
How it's calculated
Your maximum heart rate is estimated with the Tanaka formula: 208 − 0.7 × age. It was developed as a more accurate alternative to the old 220 − age rule, especially for people over 40. Any age-based formula is only an average, though; individuals commonly sit 10 or more beats above or below the prediction. If you know your real maximum from a hard, well-paced effort, trust that over the estimate.
If you enter a resting heart rate, the zones use the Karvonen (heart-rate reserve) method: resting HR + zone percentage × (max HR − resting HR). This accounts for fitness, because a lower resting heart rate widens your working range. If you leave resting heart rate blank or enter 0, the zones are simple percentages of your maximum. Measure resting HR in the morning, before getting up, over a few days.
The five zones are 50–60%, 60–70%, 70–80%, 80–90% and 90–100%. Zone 1 is recovery, zone 2 is easy aerobic work, zone 3 is tempo, zone 4 is around threshold and zone 5 is maximal effort. Heart-rate reserve percentages give higher numbers than plain max HR percentages at the low end, so do not mix the two methods when comparing.
Heart rate lags behind effort by a minute or two and drifts upward in heat, with dehydration, caffeine, poor sleep or illness. Wrist sensors are also less reliable than chest straps during intervals. Use your zones together with breathing: in zone 2 you should be able to speak in full sentences. If the number and your breathing disagree, slow down.
For most goals, spend the majority of your training time in zones 1–2 and a smaller share in zones 4–5. That pattern underpins the Couch to 5K plan and the HYROX training plan. If you take beta-blockers or other medication that affects heart rate, or have a heart condition, these zones will not apply; ask your doctor for guidance.
| Zone | Intensity | How it feels | Main use |
|---|---|---|---|
| Zone 1 · recovery | 50–60% | Very easy, relaxed breathing | Warm-ups, cool-downs, recovery days |
| Zone 2 · easy aerobic | 60–70% | Comfortable, can talk in full sentences | Aerobic base, endurance, fat use |
| Zone 3 · tempo | 70–80% | Steady, talking in short phrases | Tempo runs, race-pace practice |
| Zone 4 · threshold | 80–90% | Hard, only a few words at a time | Threshold intervals, raising race pace |
| Zone 5 · max effort | 90–100% | Very hard, cannot talk | Short intervals, sprints |
Frequently asked questions
What is zone 2 heart rate?
Zone 2 is an easy aerobic intensity, about 60–70% of your maximum heart rate or heart-rate reserve. It should feel comfortable enough to hold a conversation in full sentences. Training here builds your aerobic base, improves how well your muscles use oxygen and fat, and is easy to recover from, so you can do a lot of it.
How do I calculate my zone 2 heart rate?
Estimate your max heart rate as 208 − 0.7 × age, then take 60–70% of it. For a 40-year-old that gives a max of 180 bpm and a zone 2 of roughly 108–126 bpm. With the Karvonen method, using your resting heart rate, the range sits higher. The calculator does both automatically.
What is the most accurate formula for max heart rate?
The Tanaka formula, 208 − 0.7 × age, is generally more accurate than 220 − age, particularly for older adults. But every formula predicts an average, and your true maximum may differ by 10 bpm or more. The only way to know it is a carefully paced all-out effort, ideally after medical clearance if you are new to exercise or have health concerns.
What is the Karvonen formula?
The Karvonen formula sets training zones using heart-rate reserve, the gap between your maximum and resting heart rate. Target HR = resting HR + intensity % × (max HR − resting HR). Because it includes resting heart rate, it adjusts zones for your fitness level and usually matches perceived effort better than a plain percentage of max heart rate.
Why is my heart rate so high when I run slowly?
It is common, especially when you are new to running. Your aerobic system is still developing, so even slow running can push you above zone 2. Heat, dehydration, poor sleep, caffeine and stress all raise heart rate too. Walk-run intervals help you stay in range, and your pace at the same heart rate will improve over weeks.
How much time should I spend in each heart rate zone?
A common approach for endurance is roughly 80% of training time at low intensity (zones 1–2) and 20% at moderate to high intensity (zones 3–5). Beginners can spend almost all their time in zones 1–2 for the first months. Hard sessions are more productive when easy days are truly easy.
Is a wrist heart rate monitor accurate?
Wrist monitors are usually accurate enough for steady, easy efforts, but they can lag or misread during intervals, cold weather or with a loose strap. Chest straps measure the heart's electrical signal and are more reliable for hard sessions. If a reading looks wrong, check it against how your breathing feels.
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General fitness information, not medical advice. Check with a doctor if you have a medical condition, are pregnant or have an injury.