Zone 2 heart rate calculator

Zone 2 is easy, steady endurance riding: 81 to 89 % of your lactate threshold heart rate, about 60 to 70 % of max heart rate, or 56 to 75 % of FTP in power. With an LTHR of 165 bpm that is 134 to 148 bpm. You should be able to talk in full sentences the whole time.

Calculator

I know my

Threshold heart rate (LTHR)

bpm

Your Zone 2

134–148bpm

Check it on the bike: you can talk in full sentences, breathe through your nose and could keep going for hours.

81–89 % of LTHR (Friel)

How the Zone 2 calculator works

Zone 2 is easy, steady endurance riding: hard enough to train your aerobic system, easy enough to keep going for hours. You can set it from four different numbers, and the calculator shows the range for the one you pick. It is one of the free LeCoach cycling calculators.

You know your	Zone 2 is	Default input	Your Zone 2
Threshold heart rate (LTHR)	81–89 % of LTHR (Friel)	165 bpm	134–148 bpm
Max heart rate	60–70 % of max	185 bpm	111–129 bpm
Max and resting heart rate	60–70 % of heart rate reserve (Karvonen)	185 and 50 bpm	131–144 bpm
FTP	56–75 % of FTP (Coggan)	250 W	140–188 W

Worked example. Your lactate threshold heart rate is 165 bpm. The bottom of Zone 2 is 81 % of 165, which rounds up to 134 bpm. The top is one beat below where Zone 3 starts at 90 %, so 148 bpm. Your Zone 2 is 134–148 bpm. If you use power instead, an FTP of 250 W gives a Zone 2 of 140–188 W.

Which method should you use?

LTHR is the most precise heart rate method, because it follows where your own threshold sits. Find it with a 30-minute solo time trial: your average heart rate over the last 20 minutes is close to your LTHR.
Max heart rate is the quickest, but also the roughest. Notice how low the default range is: 111–129 bpm against 134–148 bpm from LTHR. Two riders with the same max can have very different thresholds. If you only know your age, the max heart rate calculator gives an estimate; at 40 the Tanaka formula says 180 bpm, which puts Zone 2 at 108–125 bpm.
Heart rate reserve adds your resting heart rate and usually gives more realistic easy zones than a plain percentage of max.
FTP gives Zone 2 in watts. Power responds instantly, while heart rate lags and drifts, so power is the better guide if you have a power meter.

Heart rate and power zones do not line up perfectly. Use both if you can, and see the heart rate zone calculator for all your zones.

Check it on the bike: the talk test

Whatever the numbers say, Zone 2 should pass a simple check. You can talk in full sentences, breathe through your nose and could keep going for hours. If you can only manage a few words, you are above Zone 2. If it feels like nothing at all, you may be in Zone 1, which is fine for recovery but less of a training stimulus.

The talk test is also your safety net when the numbers are off. A wrong max heart rate or an old FTP puts your zone in the wrong place; your breathing does not lie.

Want this worked out for you every day? LeCoach builds your training around your own numbers.

Try LeCoach for free

How much Zone 2 do you need?

Zone 2 is the base of endurance training. It builds your aerobic engine, improves how well you use fat as fuel and makes you more durable late in long rides. It costs little recovery, so you can do a lot of it. That is why most structured plans spend the majority of their time at this intensity. Our guide to Zone 2 cycling explains what it does in more depth.

But more is not always better. A few things to keep in mind:

Time matters. If you train five or six hours a week, filling them all with Zone 2 may leave you fit for long rides but short of top-end power. Some harder work is part of a good plan.
Many coaches use a rough 80/20 rule of thumb: most training time easy, a smaller part hard, and little in between. Read more in polarized training for cyclists.
Easy has to stay easy. Zone 2 rides that creep into Zone 3 leave you tired without the benefit of real intensity.

For two sides of the debate, read how much Zone 2 cycling do you need? and why you should be doing less Zone 2.

Common mistakes

Using 220 − age for max heart rate. It can be 10 bpm or more off, and your whole zone moves with it.
Riding by heart rate in the first ten minutes. Heart rate takes time to rise. Ride by feel or power until it settles.
Chasing the top of the range. Zone 2 is a range, not a target. Most of the benefit comes from time spent in it, not from riding at its ceiling.
Ignoring heat. On a hot day your heart rate runs higher at the same power. Holding a Zone 2 heart rate then means riding slower. That is normal.
Using cycling zones for running. Heart rate is usually a little higher when running at the same effort. Set separate zones for each sport.

When your Zone 2 changes

After a fitness gain, your LTHR or FTP rises and Zone 2 moves up. Retest every couple of months.
On long rides, heart rate drifts upward at the same power, especially late in the ride and in heat.
When you are tired or getting ill, heart rate can be unusually high or low for the effort. Trust the talk test.
After a break, retest before you train by your old numbers.

LeCoach builds your Zone 2 rides from your own zones and decides how much easy riding your plan needs, instead of a one-size rule.

Sources

Friel J. The Cyclist's Training Bible, 5th edition. VeloPress, 2018.
Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate: a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae, 1957;35(3):307-315.
Coggan AR. Power training levels. TrainingPeaks.
Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance, 2010;5(3):276-291.

Frequently asked questions

What is my Zone 2 heart rate?

The most accurate answer is 81 to 89 % of your lactate threshold heart rate. With an LTHR of 165 bpm, that is 134 to 148 bpm. If you only know your max heart rate, use 60 to 70 % of it, but expect that range to be less precise. Always check it with the talk test.

Is Zone 2 60 to 70 % of max heart rate?

In five-zone models based on max heart rate, yes. With a max of 185 bpm that is 111 to 129 bpm. This method ignores where your threshold sits, so for well-trained riders it often comes out too low. Zones from threshold heart rate or heart rate reserve usually fit better.

What is Zone 2 in watts?

In the Coggan power zones, Zone 2 (endurance) is 56 to 75 % of FTP. With an FTP of 250 W, that is 140 to 188 W. Power is a more direct guide than heart rate because it does not lag or drift, so use it if you have a power meter.

Why does my heart rate drift out of Zone 2 on long rides?

This is called cardiac drift. As you warm up, lose fluid and tire, your heart beats faster to deliver the same power. It is stronger in heat. If you hold a Zone 2 heart rate, your power drops; if you hold Zone 2 power, your heart rate rises. Both are normal.

How much Zone 2 should I do per week?

It depends on your total hours and your goals. Most plans spend the majority of training time easy, often with a rough 80/20 split between easy and hard. If you train only a few hours a week, a larger share of harder work can make sense. More Zone 2 is not automatically better.

Is Zone 2 the same for running and cycling?

No. At the same effort, heart rate is usually a little higher when running, because more muscle mass is working and you carry your weight. Test for a threshold heart rate in each sport, or at least expect your running Zone 2 to sit a few beats higher.