Heart rate zone calculator for runners
Five zones in beats per minute, from whatever you know about your heart. Age alone gives an estimate; a resting heart rate sharpens it; a threshold heart rate from a hard effort replaces the guesswork altogether.
| Zone | bpm | What it is for |
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How to use this
Fill in what you know and leave the rest at zero. Age alone gives you zones from an estimated maximum. Add your resting heart rate and the zones are drawn from your heart-rate reserve — the gap between resting and maximum — which fits a fit person far better than percentages of max alone. If you have measured your lactate threshold heart rate in a hard, even 30-minute run, type it in and the zones are built from that instead, ignoring the estimates entirely.
The result names the method it used and the number it anchored to, so you always know whether you are looking at your own physiology or a population average dressed up as one.
The three methods, in the order the calculator prefers them
Threshold (Friel). Zones as percentages of your lactate threshold heart rate: Zone 2 from 85 per cent, Zone 4 from 95, Zone 5 from threshold itself upward. The most personal, because the threshold is measured rather than guessed. Reserve (Karvonen). Each zone is a share of the gap between resting and maximum, added back to resting. Two runners the same age with resting rates of 45 and 70 get usefully different zones, as they should. Age (Tanaka). Percentages of an estimated maximum of 208 minus 0.7 times your age. A fair starting point, and the one to move away from as soon as you have a better number.
What heart rate is good at, and what it is not
Heart rate tells you what a run cost, which pace cannot. Up a hill, into a headwind or on a hot evening, the same pace sits in a higher zone, and the monitor says so. What heart rate is poor at is the first few minutes of anything — it lags behind effort — and short intervals, which are over before it catches up. For those, pace or feel is the better guide, and the training pace calculator gives you the matching pace ladder from a recent 5K.
Where these numbers come from
The zones are the ones the Outrunr app draws for a runner with the same inputs — the same three methods, the same percentages, the same order of preference — ported to this page and pinned to the app's own test fixtures so the two cannot drift. The maximum heart rate estimate is Tanaka, Monahan and Seals (2001); the reserve method is Karvonen; the threshold zones are Joe Friel's. In the app, a heart-rate monitor worn on a few hard runs replaces these estimates with your measured threshold and maximum.
Common questions
Which heart rate zone method is best?
The one built on the most personal number you actually have. A lactate threshold heart rate measured in a hard run (Joe Friel's zones) beats everything, because it is your threshold, not a population average. Next is heart-rate reserve (Karvonen), which uses your resting heart rate to personalise the age formula. Age alone is the fallback. This calculator uses that order automatically: give it a threshold and it ignores the rest; give it only an age and it says so.
Is 220 minus age wrong?
It is older and less accurate than the formula used here, 208 minus 0.7 times age (Tanaka and colleagues, 2001), which was fitted to a much larger sample. Both are population averages: the real maximum of a healthy 35-year-old can sit anywhere from the 170s to past 200. Neither replaces a measured maximum or a measured threshold; both are better than nothing.
How do I find my lactate threshold heart rate?
The field test coaches use is a 30-minute run on your own, as hard as you can hold evenly for the whole half hour — not a race, where company drags you out too fast. Your average heart rate over the final 20 minutes is a good estimate of threshold. Do it rested, on flat ground, with a chest strap rather than a wrist sensor if you can. Repeat it every couple of months as you get fitter.
Why is Zone 2 so low?
Because true aerobic running sits well below the effort most people call easy. In heart-rate terms it is roughly sixty to seventy per cent of your reserve, which for many runners is a pace that feels almost too slow. That slowness is not a flaw in the formula; it is the zone doing its job. If your easy runs sit in Zone 3, your hard days will suffer for it.
Do heart rate zones and pace zones match?
On a flat, cool day after a good night's sleep, broadly yes. Heart rate lags behind effort by a minute or so, drifts upward in heat and over a long run, and is pushed around by caffeine, stress and poor sleep — so the same pace can land in different heart-rate zones on different days. Use pace when the conditions are fair and you have a recent race; use heart rate on hills, in heat and when you don't. The training pace calculator gives you the pace ladder.
Is anything stored?
No. The calculation runs in your browser. Nothing is sent anywhere and nothing is saved.
More free tools
Zones from a formula are a start. Zones from your own runs are the finish.
Pair a heart-rate monitor with Outrunr and it learns your real threshold and maximum from the sessions you run, re-draws your zones from them, and tells you after every run how much of it was truly easy.