Two ranges of heartbeats a minute: one for moderate exercise and one for vigorous. They come from your estimated maximum heart rate, and they are guides to how hard you are working rather than targets you have to hit.
Key terms
- Maximum heart rate — the fastest your heart is estimated to beat during all-out effort. Estimated from your age, not measured.
- Moderate effort — 50% to 70% of that maximum. Brisk walking, easy cycling.
- Vigorous effort — 70% to 85%. Running, swimming laps, a hard class.
How it works
MedlinePlus, from the U.S. National Library of Medicine, gives the estimate directly: subtract your age from 220. The two zones are percentages of that figure.
Target zones
maximum = 220 − age · moderate = 50–70% · vigorous = 70–85%
At 40 the estimated maximum is 180 beats a minute: moderate is 90 to 126, and vigorous is 126 to 153.
The zones meet at 70% rather than leaving a gap. That figure is the boundary between moderate and vigorous, so a heart rate sitting exactly there is the top of one and the bottom of the other.
Why this is an estimate and not a measurement
The word MedlinePlus uses is approximate, and it matters. 220 minus your age describes an average across a population; real maximums scatter widely around it, and two healthy people of the same age can differ by twenty beats a minute or more. Fitness, medication and genetics all move it.
So a zone that feels wrong probably is wrong for you. The talk test is a better guide day to day: during moderate activity you can hold a conversation but not sing, and during vigorous activity you can manage only a few words between breaths. If the monitor and your breathing disagree, believe your breathing.
How to use this calculator
- Enter your age to see both zones.
- Check your pulse mid-exercise, at the wrist or with a monitor, and compare it with the range.
- Use the moderate zone for most sessions and the vigorous one for shorter, harder efforts.
- Cross-check against the talk test. Where the two disagree, trust how you feel rather than the number.
Frequently asked questions
How do I take my pulse without a monitor?
Place two fingers — not your thumb — on the inside of your wrist or on the side of your neck, count the beats for 15 seconds and multiply by four. Do it as soon as you pause, because the rate starts dropping within seconds of stopping.
My heart rate goes above the vigorous zone. Is that a problem?
Not necessarily, since the maximum is only an estimate and yours may genuinely be higher. But a rate that feels alarming, or comes with chest pain, dizziness or unusual breathlessness, is a reason to stop and speak to a doctor rather than something to work through.
Does medication affect this?
Yes. Beta blockers in particular lower both resting and maximum heart rate, so the zones here will read too high. If you take anything that affects heart rate, ask your doctor what range applies to you and use effort-based guides instead.
Are there better formulas than 220 minus age?
Several alternatives exist and some fit older adults more closely, but all of them estimate the same unmeasured quantity. The only accurate way to know your maximum is a supervised exercise test. This page uses the formula MedlinePlus publishes.
What if I am just starting out?
Aim at the lower end of the moderate zone and build gradually. Most public health guidance is built around accumulating moderate activity across the week rather than reaching any particular heart rate in a single session.
