The best power meters are the ideal tools to quantify your workouts, if you want to get the most out of your training.
But, as with most things in cycling, there is a huge variety of options out there – and what's best for one rider isn't necessarily the best power meter for all. It depends on the features you're after, the specification of your bike and - ultimately - your budget.
We start this guide with our immediate product recommendations based on our testing, and then lower down we will provide you with an in-depth guide to understanding more about one of the most important technologies in cycling.
How does each power meter measure power? What does power actually mean? How is power calculated? These questions are answered below and there's even a helpful link to help you get the most out of riding with power.
Best power meters reviewed
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Best pedal based power meters
These pedals provided reliable numbers for the entirety of the testing period and didn’t have any problems connecting to the head unit, a computer or the companion phone app. The pedals are USB rechargeable via a magnetic connection, meaning no fiddling with rubber seals and ports.
The pedals provide some novel metrics, such as the amount of time you’ve spent pedalling out of the saddle and your platform offset – the degree to which you pedal with one side of your foot. More common metrics such as left-right balance are also present, although a cheaper single sided version is available which doesn’t have these capabilities.
Stopping the pedals getting a perfect 10/10 is the unfortunate pedal weighting, which does make clipping in and out a little more difficult than with other systems. If fast-starting crits are your thing, then that might be a concern. The Look cleat system is used on these pedals.
Read more: Favero Assioma Duo power meter pedals full review
Garmin's Rally pedals are a progression from the Vector 3. They've seen some notable improvements, firstly, a better battery door design which appears to eliminate issues with water ingress. Secondly, clever engineering means that you can swap the spindle between pedal bodies - using RS (Shimano), RK (Look) and XC (SPD-SL) style pedals and keeping the same power meter unit, although the pedal body conversion kits are expensive.
The pedals look great, and our tests showed they worked extremely well, providing accurate readings with no frustrating drop outs or spikes. There's a single sided option as well as two sided power measurement.
These lost marks because they're a lot more expensive than the competition, and changing the spindle is a fairly fiddly job, that we don't expect multi-discipline riders would do as regularly as many swap bikes.
Read more: Garmin Rally RK200 power meter full review
Durable and super reliable, the Wahoo Powrlink Zero dual sided power meter pedals are a high-quality product for those who prefer the adjustability of the Speedplay cleat/pedal platform – and they’re fairly priced compared to the competition too.
Incredibly easy to set up and use, the build quality is superb and there were no pairing issues either.
We were impressed by their accuracy too, although with the single caveat being that the pedals appear to ‘smooth’ slightly, meaning that peak sprinting power appears lower for shortest time durations.
Post-ride analysis on the Wahoo app includes left/right balance (with the dual sided version), average and max power, TSS, normalized power, power curve and time in zones – which covers most training needs. You don’t get pedalling dynamics data though, such as torque effectiveness or pedal smoothness, which can be found on Garmin and Favero models.
Since the new Wahoo design uses a stainless steel rim that mates with the cleat, we were impressed to find they were looking almost as good as new after our six month testing period.
Read more: Wahoo Powrlink Zero dual-sided power meter pedals - long-term review
Pedal power meters that are compatible with off-road shoes and riding are a rare beast. Garmin have answered the call with a off-road version of the Rally pedal using the popular and reliable Shimano SPD pedal body and cleat.
Accuracy is +/-1 per cent and there's a wealth of data available through your bike's head unit and the Garmin Connect app giving you all the power data you could possibly want.
The pedal has quite a high stack height which does make it more vulnerable to rock strikes and possible damage. However our tester found that this isn't so much of an issue for gravel riding due to the terrain and high bottom brackets, but is something to consider if you want to ride on a mountain bike.
To increase the utility you can swap the power spindle into a road pedal body so you can use across different types of bikes. However, this is a time consuming job and not one for every ride so you'll only really get the benefit of being able to swap the pedals between bikes if you ride more than one with off-road shoes.
Read more: Garmin Rally XC200 power meter pedals full review
Best crank based power meters
4iiii has delivered a reliable and inexpensive left-side crank that, at nine grams, is one of the lightest power meters you can get on the market. Compatible with Shimano cranksets, the Precision 3.0 uses the same spec of power meter regardless of whether it’s fitted to a 105 crank (which we tested) or a Dura Ace model.
The 4iiii Precision only measures left leg power, but you can easily adjust the scale factor on the 4iiii app to account for a known imbalance in your power output between your legs.
Our testing found that it is sufficiently accurate and consistent to itself, meaning the Precision 3.0 is a useful training tool for those wanting to track their progress using power. We also experienced no issues with regards to water ingress.
Installation is very easy, as is switching between bikes. Calibration using any bike computer or the 4iiii app makes usability brilliant. Being crank based it doesn’t affect your choice of pedals and cleat system, either.
Read more: 4iiii Precision 3.0 105 R7000 single side power meter review
A previous winner in our Editor's Choice awards, the Quarq proved to be accurate, durable and reliable, without being anywhere near one of the most expensive on the market.
It's good to know that while we tested the carbon version, there's also an alloy Quarq DZero power meter for nearly half the price.
Our tester escaped dropouts and power spikes during testing, and found the data reliable - reading about four watts above a Wahoo Kickr, which is a reasonable number accounted for by drivetrain losses.
The Quarq DZero is a solid unit for those seeking easy, reliable, and accurate numbers from a power meter.
Read more: Quarq DZero power meter review
Shimano's first crack at a power meter was a reliable and easy to use dual-sided meter that looked the business and was within around 10 watts of the reading from a Tacx Neo turbo.
We've listed it in our 'best of' guide because it's an option that's still available to buy, although it's now been superseded by the 12-speed Dura-Ace R9200 power meter, while there's a new Ultegra R8100 12-speed power meter available from Shimano as well. We've used the Dura-Ace power meter as part of an overall review of the new Dura-Ace R9200 groupset, but we haven't yet dived into the detail of its performance.
Read more: Shimano Dura-Ace R9100-P power meter review (opens in new tab)
With its comprehensive range of chainrings, chainsets and bottom brackets, a power meter is a natural extension of its product portfolio for FSA. It paired up with German power meter experts Power2Max to develop the Powerbox crank-based power meter.
We got hold of the alloy FSA Powerbox for our test, but there are also full carbon versions available, although expect to pay about double the price.
When we tested the Powerbox, we found that it was accurate and reliable and also coped well with the odd dousing with a hose pipe. It's ANT+ and Bluetooth compatible, comes in carbon and alloy versions and with a wide range of chainring size options, including super compact (opens in new tab) options. It's on the heavy side, though, relative to other power meter options and only available with a 30mm diameter spindle so it won't fit all bottom brackets.
Read more: FSA Powerbox power meter review
The Best Power Meters Explained
What is a power meter?
A power meter is a device fitted to a bike that measures the power output of the rider.
Strain gauges deflect slightly when a force is applied. By measuring this torque and combining it with angular velocity, power (measured in watts) can be calculated.
It's a good way to gauge your effort while riding that's less prone to extrinsic factors than heart rate measurement. Some riders swear by regularly testing their functional threshold power to measure how training is going. You can find out what is FTP in cycling and how to improve it on our dedicated page.
What does watts mean on a bike?
Watts are the energy required to a move a mass a certain distance in a known time period. So in bike speak, the mass is you plus your bike, and the distance is the ground covered.
Moving a bike, though, is a far more complicated scenario, as its resistance to motion is far from consistent. In layman's terms, then, this equates as: power = force x velocity.
And that is the key to understanding how a power meter works. It's essentially applying that equation to a given part of the bike - be that bottom bracket axle, crank, hub, pedal axle etc.
Accurate measurement of this force is one of the biggest challenges power meter manufacturers face, placing the upmost importance on the smallest of details such as the placement of the gauges, the quality of the gauges themselves and even the temperature of the measured material.
How do the best power meters work?
Currently, the best power meters can be placed in four key areas of a bike and how they work will depend on their location, although they will all use an array of strain gauges.
Of course, each has its own advantages and disadvantages.
Pedal-based systems are easy to fit and change between bikes, but can be less accurate owing to the complexity of the force measurement. What's more, being exposed makes them at greater risk of damage.
Popular examples include the Garmin Rally and Favero Assioma and Wahoo has recently launched the Powrlink Zero Speedplay-compatible power meter. Power meters of this type can also be single or double-sided.
Bottom bracket systems can be accurate and low maintenance. However, installation is more difficult and is made all the more complicated by the varying bottom bracket standards available today.
Factor in that a system of this type may not fit your bike and it is also possible that you have to run a different brand chainset to the rest of your groupset. Examples include Rotor INPower.
Chainring based power meters can be very accurate but it is worth factoring in that they don't actually measure individual left/right power, although they can estimate it.
Similar to bottom bracket systems, they are not as easy to swap between bikes, unlike pedal-based systems, and there can be compatibility issues. Examples include the fabled SRM (the original power meter), Power2Max and Quarq.
Crank arm-based systems can be relatively easy to swap between bikes. Like pedals, they have the potential to be single or double-sided and popular examples include the Stages crank arm and 4iiii Precision meter.
What is the difference between single, double and combined power meters?
You can buy single-sided power meters that measure power from one side, usually the left, and then double the reading to estimate your total power output from both legs.
A single-sided only measurement means doubling a single leg's power may not be a fully accurate representation of your power, but it can mean they are more affordable.
It may be worth checking if you have significant imbalances before opting for a single-sided meter. Note a 48/52% balance between legs is common.
Combined power meters effectively combine the power from both right and left legs and do not measure it independently. An example would be an SRM power meter.
Note that these systems, although accurate, will not differentiate which leg the power comes from.
Left/Right side power meters, or double sided power meters are found on more modern and more expensive power meters that have gauges in multiple locations, such as pedals and some crank-based units.
This can be useful in establishing if you have an imbalance (one leg much more powerful than the other) and for working on pedalling technique. It can also be used if you are recovering from a single leg injury.
Dual sided measurement is limited to power meters that measure power in more than one location, such as pedals, but also more expensive crank-based units, like Rotor 2InPower.
Which power meters work with Garmin and other cycle computer connectivity?
Everything rated here and the vast majority of power meters transmit via ANT+, allowing them to connect to most bike computer systems, including Garmin.
Most power meters also offer Bluetooth Smart connectivity - a handy tool for connecting to indoor training apps such a Zwift and Trainer Road, or smartphones, as well as for practicalities such as updating power meter software. Most cycling computers also now have Bluetooth connectivity built in.
Our guide on the indoor training apps for cycling compares the best on the market and helps you identify what one you are most suited to. If you are wondering about power meters and turbo trainer compatibility, our page on best smart turbo trainers includes the latest models.
If the current climate means slim pickings on indoor trainers, or finances mean having to choose one or other, you can always bypass the smart trainer altogether and just use a power meter and simple turbo trainer. You'll need a couple of other sensors but can still work out as a much cheaper Zwift set up and you have the bonus of outside use once warmer weather arrives.
Do power meters measure cadence?
Yes, even if you are using bottom bracket based power meters, there will be the supporting software to enable you to measure cadence, as it's necessary for the power meter to derive your power output.
Are power meters worth the money?
There are lots of schools of thought about how to train and race effectively. Some people swear by tracking data, others steer well clear, but as with most things in life, most think it's about striking the right balance. Our feature on using a power meter in training is a really great insight into what the experts say, acknowledging the best power meters as helpful tools, but not to lose touch with your rider instincts.
Why are the best power meters so expensive?
There is an incredible variety of power meters now on the market, which has helped their popularity, volume of sales and therefore helped bring the prices down. However, it's still very much a developing technology, which has to be accounted for in the end price.
From our experience, it's a 'you get what you pay for' product. The best power meters will have invested a significant amount of research and development in ensuring that the end product is consistently accurate, robust enough to withstand forces and harsh environmental conditions and to develop the supporting software.
Entry level - typically £250-£400/$300-$500
At this price you are likely to get a single-sided measurement that doubles the reading to estimate both legs. Stages 105 cranks are available at this price, as are 4iiii and the outgoing Garmin Vector 3 single sided power meter.
Mid-level - typically £550-£800/$700-$1,000
Mid-price starts to see pedal-based systems and dual-sided meters. Crank and chainring systems also become available. Professional athletes are increasingly using meters at this price point. Favero Assioma pedals are a fine example.
Top end - £900/$1,200 +
At the top of the market, we find dual-sided measurement and crank and spindle based systems. Examples include the Rotor 2InPower and SRM.
How do I use a power meter?
If you want to learn about how to ride with a power meter, it's worth reading our guide on how to train with a power meter. It has lots of useful information about how get the most out of your gadget and how to apply the numbers to your training.
How we test
Cycling Weekly has a team of testers with vast experience of testing bikes, components, clothing and accessories across a wide range of prices and spec levels, so they know bikes and tech inside out and have the experience to know what makes a great cycling product.
Our experience means that you'll have a consistent, in depth viewpoint, which is reflected in our product scoring. You can find out more on our How We Test page.
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