Road bike sizing guide – Trek Bicycle

Choosing the right frame size is a crucial part of getting the most out of your road bike. It's not just about comfort: when a road bike fits properly, it's more efficient, easier to handle and better at transferring your power to the road. Read on to learn about road bike sizing and get help finding your perfect fit.

How to choose your road bike size

Bikes come in a range of sizes, and the best fit for you depends primarily on your height and inside leg measurement. That's true whatever your gender, as gender matters far less in finding the bike that's best for you than other factors.

We recently transitioned Trek road bike sizing from numerical sizing to alpha sizing to help make it even easier to find the right size for you.

Want help finding your perfect fit? Our Size Finder tool helps determine your ideal bike size – all you’ll need is a measuring device to measure your height and inside leg measurement!

How to measure your inside leg

Put on a pair of cycling shorts and stand barefoot with your back straight and against a wall. Use a ruler to carefully measure between your legs from your crotch down to the floor.

Expert advice from Trek

Need a hand? We’re here for you! You can connect with your local Trek retailer directly or call and chat online with us at Trek Headquarters, Monday to Friday, 8 a.m. to 6 p.m. CT, and Saturday and Sunday, 9 a.m. to 6 p.m. CT.