With three power sources in the mix (power meter pedals, power meter cranks and a smart trainer, for example), we can start to get a feel for which – if any – are the outliers. When used to record data simultaneously, we can quickly determine whether the lines on the graph (a trace of your power output across a ride) match up or not. While outside, we always used two on-bike power meters simultaneously (again, using power meters measuring power from different locations on the bike). When riding inside, we measured power from three sources – two on-bike power meters (for example, power meter pedals and power meter cranks and an Elite Direto XR smart trainer). While we don’t expect every number to match up exactly, accurate power meters should agree very closely on the power you are producing at any given moment.Īlso, each power meter was tested on a series of indoor rides, with data also validated on outdoor rides. How have we determined the accuracy of a given power meter? We tested multiple power meters from a wide variety of brands to cross-reference against one another, which enables us to put those claimed accuracy levels to the test. Typically, the more expensive a power meter, the tighter the claimed margin of error will be (though, again, this is not always the case).Īs with any measurement device, accuracy should be a given, but there are occasionally differences between what a brand claims and what the product delivers. Most manufacturers will claim their power meters are accurate to within +/- 1 to 2 per cent. It’s crucial that any device used to measure something is accurate, so we have rigorously tested all the power meters included in this list. Power meter accuracy and how we tested itīikeRadar’s technical writer, Simon von Bromley, tested each power meter indoors on an Elite Direto XR smart trainer, with results also validated outdoors on his Giant TCR long-term test bike.

We have also tested the accuracy of all the power meters listed here. Our testing took into account ease of installation, how each power meter performed on the bike while riding, and whether it’s likely to stand up to long-term use. Our experience using dual-sided power meters (which measure power output from each leg independently) shows this isn’t the case, though. While single-sided power meters are typically cheaper, they also assume your power balance (the percentage of total power each leg is producing) is perfectly even at all times.

We focused our testing on power meters that measure total power, rather than single-sided power meters, (which measure power output from one leg and double it to estimate total power) because these give the most accurate picture of your power output. Products from across the price spectrum have been included as well as different power meter types, from crank-based power meters and spider-mounted power meters, to pedal power meters. We tested seven power meters from leading brands through the first six months of 2021, and this list of the best power meters brings together the most reliable and user-friendly power meters we tested. With this knowledge, you can calculate your training load, target precise effort levels through your training zones, track improvements in your fitness, determine how many calories you’re burning, and more.Ĭombine this data with information from a cycling computer and heart rate monitor, and it can be a very powerful tool in the right hands. Your power is measured in watts (one watt equals 1 joule per second), giving you a precise calculation of how much energy you’re putting through the pedals at any given moment. A power meter is, in simple terms, a set of moving scales that measure your power output and is measured as a calculation of torque (how hard you’re pushing the pedals) multiplied by cadence (how fast the pedals are turning – or revolutions per minute).

Double sided coin cheap