Road bike frame size calculator

Road Bike Frame Size Calculator

Road bikes, as the name implies, are bikes that are built for maintaining decent to high speeds while you’re riding on paved roads and asphalt. These are sometimes referred to as racing bikes because the type is often used on racing circuits.

This calculator will recommend a road bike frame size based on your measurements. If you don't know your leg length, you will get a range of frame sizes to try out.

Road Bike Frame Size Calculator


Rider Information

  • Required
  • what's this?
  • Required
  • what's this?
rider height and length

How To Use Our Road Bike Frame Size Calculator

Road bikes and mountain bike frame sizes are slightly different and the units used in bike sizes vary depending on type and brand. Road bike sizes are usually given in centimeters, while mountain bike frame sizes are quoted in inches. Fortunately, our bike size calculator takes away the guesswork as it suggests road bike frame size  in either inches or centimeters alongside manufacturers bike size charts.

Choosing the correct road bike frame size easy. All you need to do is measure your height and your inside leg (inseam) and then enter those measurements into our  bike size calculator.


Simply stand on a flat surface, upright against a wall with your legs together and shoulders back. Make sure you take your shoes off. Place a pencil on top of your head and holding it parallel to the floor make a little mark on the wall.



Stand with your back against a wall (no shoes). Place a book or ruler between your legs at your crotch. Get a friend to measure from the floor to the top of the book/ruler, making sure it is level.

leg length

Can I Use The Bike Size Calculator For Women’s Road Bikes?

Yes, typically women’s specific bikes have different road bike frame sizes to unisex bikes, but they are sized in the same way. Women tend to have shorter upper bodies than men, so the frames are shaped differently.

Women's bikes tend to have shorter top tubes compared to a similarly sized unisex bike. This makes the bike slightly shorter than a unisex bike so a female cyclist will feel less stretched out on a women’s bike.

As this doesn’t affect the seat tube length (saddle height) or stand-over clearance, our bike size calculator is suitable for both unisex and women’s specific bikes and the information in this bike size guide is relevant to women’s road bike sizes.


Sometimes our bike sizing calculator will recommend two different bike frame sizing options. This means that both the larger and smaller road bike frame size or mountain bike frame size recommended will be suitable It is a personal choice but, if you are unsure, there are a couple of rules of thumb:

Road bikes - choose the smaller size. This is because it is easier to make a small road bike bike bigger (by raising the saddle or fitting a longer stem) than it is to make a big road bike smaller.