- Speed is the target speed in miles per hour.
- Weight is total vehicle weight including the rider(s) and cargo.
- Grade: 0 percent is flat ground and 100 percent is a
45 degree angle. The grade is automatically set to 0 unless another
number is entered.
This calculator provides an estimate of how much power it
will take to go on flat ground or up a grade at a certain speed. It does and can not
estimate all variables such as lower than normal motor and drivetrain
efficiency, higher than normal rolling resistance, and head or tail
winds. This calculators mathematical formula is based on real world
road testing of electric scooters and bikes. It calculates the user
inputs with gravity, rolling resistance, and drag (air resistance)
to obtain the Required Power result.
Electric motors produce a high amount of torque under load so for example
an electric scooter, bike, or go kart with a 500 Watt motor and one rider could be geared to
go 15 MPH on flat ground and with the same gearing it would be able
to go up a 10 Degrees Grade at 7 MPH.
To use this
calculator to figure out what size motor to install on a custom made
scooter, bike, or go kart that is used on flat ground with some
grades up to 10 Degrees we recommend entering the desired top speed
of the vehicle, estimated weight of vehicle including the rider(s),
and a Grade of 3 Degrees. With this formula the top speed when going
up a 10 Degree Grade will be around half of what it is when
traveling on flat ground.
This calculator is designed
for brushed motors. Calculations for brushless motors will be around
10% more efficient than the results that are shown.