The power required for e-bikes depends on the type of biking you will be doing and the length of your powered ride.  Some electric bikes do offer the option for pedal assistance where the rider takes over.  Most electric bikes give the power rating in Wh (Wattage hours), which is actually the capacity of the battery.  Given the maximum speed of your ride, you can determine the range of that battery.  Given US mileage standards, a general rule for electric bikes is that you’ll use 1 W/mile for every 1 mph (miles per hour).  So if you’re riding at 20 mph, you’ll generally use 20 W per mile.  And if you have a 500W motor, your battery range will be 25 miles.  So make sure to consider this before you make a purchase.  Here’s our recommended power(wattage) for these types of biking:

• For flat terrain ONLY, a 300W motor is sufficient.
• For urban commuting on flat terrain, a 500W motor is recommended.
• For weekend riding on moderate hills, trails, or heavier loads, consider a 750W motor.
• For off-road enthusiasts or extreme terrains, a 1,000W+ motor is the best choice.

Check on your local laws and regulations on e-bikes. Many countries limit e-bike motor power:

• USA: Up to 750W for Class 1–3 e-bikes, depending on state laws.
• EU: 250W max for road-legal e-bikes.