Bike tools
Three calculators for the questions that decide a purchase: how far an e-bike will really go, whether a particular bike is legal on a UK road, and what size frame you need. No account, no email, nothing stored.
E-bike range calculator
Work out realistic range from battery watt-hours, your weight, the terrain and the assist level you actually ride in. Most published range figures assume you are lighter, fitter and on flatter ground than you are.
Uses Wh per mile by tyre type, adjusted for terrain, assist, mass and temperature.
UK e-bike legality checker
Enter the motor power and cut-off speed from a listing and find out whether the bike is a legal e-bike, needs registering as a motor vehicle, or cannot be made road-legal at all. Most high-power imports fall into the last group.
Applies the EAPC rules: 250W continuous, 15.5 mph, pedal assist, throttle limits, rider age 14.
Bike size finder
Get your frame size from height and inside leg, with the saddle height starting figure, for road, hybrid, mountain and children's bikes.
Frame size in cm and inches, plus the size letter and a saddle height in cm.
Why these three
They are the questions that most often end in a returned bike or a disappointment. A range figure that turns out to be half the claim, a machine that cannot legally be ridden to work, or a frame one size too large — each of those is avoidable with two minutes of arithmetic, and each is expensive to discover afterwards.
Every calculator on this page states the assumptions it makes and where it stops being reliable. None of them is a substitute for a test ride, but they will stop you making a mistake you could have seen coming.