Bike Size Calculator

Getting the right frame size is the single biggest factor in whether a bike feels comfortable and rides well, and it comes down mostly to your leg length rather than your overall height. This calculator uses the standard inseam method to suggest a frame size for a road, hybrid or mountain bike. Your inseam is the distance from the floor to your crotch, measured in bare feet, and it drives the calculation because it sets how far the saddle sits above the pedals and how much standover clearance you have over the top tube. Choose the type of bike you are sizing, enter your height and inseam in centimetres, and the calculator returns a recommended frame size, a size band from extra small to extra large based on your height, and a saddle height to set as a starting point. Road frames are measured in centimetres, hybrids in centimetres, and mountain bikes traditionally in inches, so the result is given in the unit that matches the type you pick, with the other unit shown alongside. Treat the figure as a well-informed starting point rather than a precise answer, because frame geometry varies between brands and models, and two bikes with the same labelled size can fit quite differently. Where you can, take a test ride and check the standover clearance and reach, and if you are between sizes think about whether you prefer a more upright or a more stretched-out position.

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For a road bike, a rider 175 cm tall with an inseam of 80 cm suits a frame around 53.2 cm (size M).

Frame sizing varies between brands, so use this as a starting point and test ride where you can. Saddle height uses the LeMond method (inseam times 0.883). Estimate only.