Heart-Rate Zone Calculator
Five training zones from your age — or personalized with the Karvonen heart-rate-reserve method if you know your resting pulse. Formulas and caveats shown. Informational only, not medical advice.
| Zone | Heart rate | Typical use |
|---|---|---|
| Zone 1 · Very light | 90–108 bpm | Warm-up, recovery |
| Zone 2 · Light | 108–126 bpm | Base endurance, fat metabolism |
| Zone 3 · Moderate | 126–144 bpm | Aerobic fitness |
| Zone 4 · Hard | 144–162 bpm | Speed and threshold |
| Zone 5 · Maximum | 162–180 bpm | Short intervals only |
How to use this tool
- Enter your age — the five zones appear from the standard 220 − age estimate.
- Know your resting heart rate (measure it in bed, first thing in the morning)? Add it to switch to the more personalized Karvonen method.
How it works
Maximum heart rate is estimated as 220 − age — the American Heart Association's rule of thumb, with the honest caveat that individual max HR varies by ±10–15 bpm around that estimate. Simple zones are percentages of that max. The Karvonen method improves on it by working with heart-rate reserve: target = resting + (max − resting) × intensity — anchoring the zones to your actual fitness.
Medications (notably beta-blockers), heart conditions, and individual physiology all shift these numbers. The AHA's own advice applies here: if you have a heart condition or take medication that affects heart rate, ask your healthcare professional what your zones should be. Training guidance, not medical advice.
Sources & references
Content last reviewed: July 2026.
Frequently asked questions
What heart rate should I exercise at?
The AHA's general guidance: moderate activity around 50–70% of maximum heart rate, vigorous around 70–85%. The zone table shows your numbers; beginners start low and build.
How accurate is 220 minus age?
It's a population average with real individual spread — your true max can differ by 10–15 bpm either way. The Karvonen option (using your measured resting HR) personalizes the zones without a lab test.
How do I find my resting heart rate?
Count your pulse for 30 seconds and double it, first thing in the morning before getting up. For most adults, 60–100 bpm is normal; well-trained people run lower.