Power zones calculator

What power zones are

Power zones split your effort on the bike into seven bands, from very easy to flat out. Each one is a share of your FTP, the most power you can hold for about an hour. Your smart trainer shows your power in watts, so you can see your zone as you ride.

Training plans use zones to say how hard each part of a ride should be. Ten minutes in zone 2 means ten minutes at a pace where you can still chat.

The seven zones

• Zone 1, up to 55% of FTP: easy spinning, to warm up or rest your legs.
• Zone 2, 56 to 75%: all day pace, the kind you can hold for hours.
• Zone 3, 76 to 90%: brisk and steady, like a lively group ride.
• Zone 4, 91 to 105%: hard but steady, close to your limit for an hour.
• Zone 5, 106 to 120%: very hard efforts of 3 to 8 minutes.
• Zone 6, 121 to 150%: short bursts of 30 seconds to 3 minutes.
• Zone 7, over 150%: sprints of a few seconds.

How the calculator works

It takes your FTP and works out each zone in watts. Zone 2 is 56 to 75% of FTP. With an FTP of 150 watts, that comes to 84 to 113 watts.

Where the numbers come from

• Zones 1 to 5 and the start of zone 6 are from Andrew Coggan's power levels on TrainingPeaks. The way each zone feels follows his own words for it.
• Coggan's table gives zone 6 no top number and zone 7 no number at all. Splitting them at 150% is widely used, for example by the power meter maker Favero.