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Fitness watches and gym machines constantly show your heart rate — but what should it be? Heart rate zones turn that number into a simple guide: how hard you’re working and what that effort is doing for your body.
This article is general information, not medical advice. If you have a heart condition, take medicines that affect heart rate (such as beta-blockers), or are starting exercise after a long break, check with your doctor first.
Step 1: estimate your maximum heart rate
Your maximum heart rate (MHR) is the highest your heart can beat during all-out effort. The simplest estimate:
MHR = 220 − age
A slightly more accurate formula for many adults (Tanaka):
MHR = 208 − 0.7 × age
For a 30-year-old, both give about 190 beats per minute (bpm).
Step 2: the five zones
| Zone | % of MHR | Feels like | Main benefit | Age 30 (MHR 190) |
|---|---|---|---|---|
| 1 – Very light | 50–60% | Easy walk, can sing | Recovery, warm-up | 95–114 bpm |
| 2 – Light | 60–70% | Comfortable, can chat | Endurance base, fat use | 114–133 bpm |
| 3 – Moderate | 70–80% | Breathing harder, short sentences | Aerobic fitness | 133–152 bpm |
| 4 – Hard | 80–90% | Few words at a time | Speed, lactate threshold | 152–171 bpm |
| 5 – Maximum | 90–100% | Can’t talk, all-out | Sprint power | 171–190 bpm |
Personalise it with resting heart rate
The Karvonen method uses your resting heart rate (RHR), measured in bed after waking:
Target = (MHR − RHR) × intensity + RHR
Age 30, RHR 60: heart rate reserve = 190 − 60 = 130.
Zone 2 (60–70%) = 130 × 0.6 + 60 to 130 × 0.7 + 60 = 138–151 bpm.
That's noticeably higher than the simple 114–133 bpm, and often feels more accurate for fitter people.
How to use the zones
Build a base in zone 2
Many endurance coaches recommend that most weekly training — often around 70–80% of it — is easy. Zone 2 builds your aerobic engine, improves fat use and is easy to recover from. If you can’t hold a conversation, you’re probably above zone 2.
Add some harder sessions
One or two sessions a week in zones 3–4 — tempo runs, brisk hill walks, interval cycling — improve speed and stamina.
Use zone 5 sparingly
Short sprints or hard intervals improve peak power but need plenty of recovery. Beginners can skip them initially.
Measuring heart rate
- Chest straps are the most accurate during exercise.
- Wrist watches are convenient; accuracy varies with fit and movement.
- Manually: count your pulse at the wrist or neck for 15 seconds and multiply by 4.
The talk test
No device? Use your breath:
- Can talk in full sentences → zones 1–2
- Can speak in short phrases → zone 3
- Only a few words → zone 4
- Can’t talk → zone 5
Find your zones
Our Heart Rate Zone Calculator estimates your maximum heart rate with either formula and shows all five zones in beats per minute — using the Karvonen method automatically when you add your resting heart rate.
Free toolTry the Heart Rate Zone CalculatorFind your target heart rate zones for exercise.Frequently asked questions
Is 220 minus age accurate?
It's a rough estimate and can be off by 10–15 beats per minute for some people. A supervised exercise test or a field test gives a better figure.
Which zone burns the most fat?
Lower zones use a higher percentage of fat for fuel, but higher zones burn more total calories per minute. For weight loss, total activity and diet matter most.
My heart rate is higher than the zones suggest — is that bad?
Heat, stress, caffeine, poor sleep and dehydration all raise heart rate. If you have chest pain, dizziness or breathlessness, stop and seek medical advice.
For general information only — not medical advice, diagnosis or treatment. Always consult a qualified doctor, pharmacist or healthcare professional. Written by the Toolsopedia team. Spotted an error? Tell us and we’ll fix it.