Get a training plan built on your zones — so every session targets the right intensity for real progress.
Cycling heart rate zones are built from an anchor: a number that everything else is measured against. This calculator offers three, from the roughest to the one a laboratory would give you, and they do not produce the same zones.
Your zones come out as percentages of the highest heart rate you can reach on the bike. It is the easier anchor to get hold of, and the rougher of the two. Use a max you have actually seen on a ride, not one a formula gave you.
LTHR is your second lactate threshold, the one usually written LT2 or anaerobic threshold: the hardest effort you can hold for roughly an hour. It is not LT1, which sits far lower and marks the top of easy riding. Your zones come out as percentages of that LT2 figure. It is the more accurate anchor for trained cyclists, because threshold moves as you get fitter while maximum heart rate barely does. The percentages below follow the cycling convention popularised by Joe Friel, closed up so the five bands touch and no heart rate falls between two zones.
This is how a lactate test reports intensity, and how the research on training distribution defines it. Instead of splitting one anchor into five slices, it uses your two real thresholds as the boundaries. Below LT1 is genuinely easy. Between LT1 and LT2 is the grey zone, hard enough to cost you recovery but not hard enough to drive adaptation. Above LT2 is the work that hurts. Enter both thresholds if you have them; enter one and the other is estimated from it.
A note on the naming, because it trips people up: LTHR in Method 2 and LT2 in Method 3 are the same threshold. LT1 is a different, much lower one, and only Method 3 asks for it. Whichever method you pick, the calculator also shows you both thresholds, estimated when you have not measured them — LT1 at around 75% of maximum heart rate and LT2 at around 87%, which are the figures in our own definition of the two. Only a lactate or gas exchange test gives you the real ones. The three methods disagree on purpose. Max-HR zones are wider at the bottom and narrower at the top; LTHR zones put more resolution where the hard work happens. If your Zone 2 feels too easy on one method and about right on the other, that is the difference showing up, not an error.
Same rider profile, both anchors, so you can see how far apart the answers land.
A long endurance ride sits between 113 and 132 bpm.
The same endurance ride now sits between 136 and 151 bpm — roughly 20 beats higher than Method 1 suggested. Neither is wrong. They answer to different anchors, which is exactly why you should pick one and stay on it.
Zone 2 is where most of your riding should happen, and it is the zone riders most often overshoot. The number on the screen says Zone 2; the legs are doing Zone 3.
The research behind it is not new. Seiler's review of how competitive endurance athletes actually train found they converge on roughly 80% of sessions at low intensity — at or below 2 mM blood lactate — with about 20% genuinely hard. Not a middle-heavy diet. Easy days easy, hard days hard.
Two practical tests, both free. You should be able to hold a full conversation in sentences, not gasped words. And your heart rate should settle within the band within about ten minutes and stay there, rather than climbing all ride.
If you cannot hold the conversation, you are not in Zone 2, whatever the anchor says. That is the signal to re-test your max or your threshold, because a wrong anchor moves every zone underneath it.
One caveat: on rides over about ninety minutes, in heat, or when you are underhydrated, heart rate drifts upward at the same effort. That drift is real physiology, not a broken zone. Judge those rides on the first hour.
Every calculator warns you not to trust the age formula. We can show you how wrong it is, because we can see the highest heart rate our riders have actually hit on the bike.
We took the peak heart rate recorded across every ride with a heart rate monitor from the cyclists training with Cycling Coach AI, kept one figure per rider — their highest — and compared it against what 220 minus their age would have predicted.
The formula does not fail evenly. Under 30 it is close enough to be useful. Past 50 it is out by 20 beats or more, and every zone built on it is out by the same proportion.
Across the whole group, 59.8% of cyclists were more than 10 beats away from their predicted maximum, and 30% were more than 20 beats away.
The measured median barely moves after 40. Riders in their sixties are reaching almost the same peaks as riders in their forties, while the formula keeps subtracting a beat a year.
Methodology: cyclists training with Cycling Coach AI who have at least 10 rides recorded with a heart rate monitor, measured on 4 September 2026. Values outside 100–225 bpm were discarded as sensor artefacts. Two biases worth stating: a peak seen while riding is a floor, not a true maximum, since almost nobody goes all-out on a normal ride — so the real gap is likely wider than the table shows. And these are cyclists who train with a structured app, not the general population.
Worth saying plainly, because a calculator that pretends to be more than it is will cost you training time.
It does not measure your maximum heart rate or your threshold. It divides up a number you give it. Give it a bad number and every zone is wrong by the same proportion.
It does not use 220 minus your age, and neither should you. Our own riders sit 15 beats above that formula on average, and the gap widens with every decade — see the numbers above.
It does not adjust for heat, altitude, illness, caffeine or poor sleep. All of them move heart rate at a fixed effort, sometimes by ten beats or more.
It does not replace power. Heart rate answers slowly and lags the effort by a minute or two, so it is poor at pacing short intervals. For anything under about five minutes, power is the better guide.
It does not know your sport. Cycling maximum heart rate typically runs a few beats below running, so zones borrowed from a running test will read slightly high on the bike.
The claims above that come from published work, with the work named.
Quick answers to the most common questions, so you can set your zones and train with confidence.
Cycling heart rate zones are effort ranges based on your heart rate that help you train at the right intensity for your goal, like endurance, tempo, or threshold.
Common reasons are an incorrect max HR or LTHR, fatigue, heat, dehydration, caffeine, poor sleep, or not wearing the sensor correctly. Re-test and adjust if your "easy" zone never feels easy.
Most base endurance rides sit in Zone 2 for many riders, but the right target is the zone where you can keep a steady conversation and finish feeling like you could do more.
Update them after a meaningful fitness change or every 6-12 weeks if you are training consistently, especially if your threshold pace or power improves.
For many cyclists, chest straps are more reliable during high intensity and in cold weather. Wrist sensors can be fine for steady riding but may lag or spike during intervals.
Heart rate drift can happen due to rising body temperature, dehydration, fatigue, or low fueling. It is normal in longer rides, and it is a useful signal to pace and fuel better.
Yes, but keep it simple. Start by learning what "easy" feels like and focus on consistency first. If you want a clear starting point, follow a cycling training plan for beginners and build your base before worrying about perfect zones.
