How much power does an electric bicycle need? Here’s a helpful guide

Electric bicycles are available in a wide range of power levels. From cute little 250 W e-bikes to massively overpowered 10+ kW motorbike-level e-bikes. But how much power is right for you? Read on to learn more!

Just a quick note before we jump into the power level comparisons: not all motor ratings were created equal.

Because of differing standards for measuring electric motor power ratings, a pair of 500 W motors from different companies can have fairly different power levels. Also, laws limiting power output in Europe and other restricted areas have forced many manufacturers to often underrate their power levels.

For example, Bosch mid-drive systems are often listed as 250 W motors, despite actual power output often being upwards of 500 W peak.

So when we discuss motor ratings, we’ll be largely taking e-bike manufacturers at their word. But keep in mind that just because two motors are labeled similarly doesn’t mean they’ll necessarily have the same power.

Lastly, if you’re the kind of person that likes to watch and listen, check out my video on the topic of e-bike power. Then read on for all of the details below!

250 W electric bicycles

The lowest power class for electric bicycles is usually the 250 W class. There are some 200 W e-bikes, but they are often smaller scooter-style bikes.

With 250 W of power, you’re basically looking at a flat land cruising e-bike. Most 250 W e-bikes will struggle to climb hills without any user-added pedaling, though mid-drive e-bikes will offer better hill climbing performance than hub motors at these low power levels due to their ability to achieve higher torque through downshifting the bike’s gears.

If you’re a heavier rider, you can still ride a 250 W e-bike as long as you are on flat terrain. The acceleration will be quite sluggish, but the bike will move you. Keep in mind that 250 W continuous is more power than most people create when pedaling.

I weigh 70kg (154 lb) and I find that 250 W can still move me around comfortably. But as soon as I hit hills, the performance diminishes quickly and the bike slows down considerably. Heavier riders shouldn’t really attempt to climb long hills on 250 W hub motors without risking damage to the motor from repeated high heat cycles. Heavier riders can sometimes still find 250 W mid-drives sufficient for small hills, especially if they want to add some pedal input, but major hills are still going to seriously degrade the performance of a 250 W ebike with a heavy rider. There just isn’t enough power or torque in a 250 W system to power heavy riders up medium-sized hills while maintaining a reasonable amount of speed.

When it comes to speed, 250 W motors are also usually limited to somewhere between 25-32 km/h (15-20 mph). Above such speeds it becomes difficult to overcome wind resistance without adding more power.

350 W – 500 W electric bicycles

The next step up in power brings an increase in acceleration. While 250 W e-bikes are sluggish to accelerate, bikes that reach closer to 500 W will pull much quicker off the line.

For lighter riders like me, this will feel like a fairly large difference. Heavier riders though will likely not feel too much of a difference on flat land, depending on the motor.

500 W Roadster Ghost e-bike (check out my review here!)

On hills, 500 W will do a much better job of powering light riders to the summit. Smaller hills may become conquerable for heavier riders. Again though, such riders won’t see a huge difference as compared to lower powered 250 W motors when it comes to any decent hill.

It should also be noted that 500 W is usually the minimum power necessary for an e-bike to surpass 32 km/h (20 mph) of speed.

750 W – 1,000 W electric bicycles

Now we’re talking! Once you’ve reached 750 W, you’re dealing with some actual power. For light riders like me, 750 W will give much more exciting acceleration off the line. This level will also start to offer good hill climbing performance.

For heavier riders, 750 W is when flat land performance starts to become more enjoyable and hills actually become consistently possible. At 1,000 W of power though, most heavy riders will be more pleased with the performance.

Speeds of 45 km/h (28 mph) are increasingly common with 750 W e-bikes. You’ll still see Bosch-powered mid-drive bikes capable of 45 km/h (28 mph) while claiming a “250 W” motor. But again, these are underrated motors and aren’t really fair comparisons to true 250 W motors.

45 km/h (28 mph) Cafe Moto Go e-bike with a “250 W motor”

1,500+ W electric bicycles

At 1,500 W, you’re starting to leave typical bicycle territory and begin encroaching upon light electric motorcycle levels. I built a 60 km/h (37 mph) electric bike using a 1.5 kW hub motor, and the performance is incredible. It doesn’t matter if you put me or a 110 kg (250 lb) rider on that bike – the thing just freaking pulls!

I recently rode the Rungu all terrain three-wheeled e-bike with a 1.5 kW Bafang BBSHD mid-drive motor. That was another great example of extreme power that can carry both light and heavy riders up the highest hills. In fact, the only time it failed to carry me up hills was when they became so steep that the bike simply couldn’t get traction in the loose dirt.

Keep in mind though that mid-drive motors at such high power levels require special chains and sprockets to keep from completely destroying themselves.

Choosing the right power level for you

I hope that the take-home message for you will be that e-bikes come in many flavors and power levels and that the right power for you is a highly personal decision.

While I’m perfectly happy commuting on a 250 W e-bike in my flat city, I’d never take anything less than 750 W off road. Others might say that it’s 1 kW of power or nothing for them. The key is to find what works for you and how much power will achieve your goals.