The right-sized bike is an important part of any roadie’s arsenal, but choosing the correct size can be difficult. It’s hard to know what size bike to get if you don’t have experience riding one before. If this sounds like you, then fear not! We’ve put together a handy guide with all the info you’ll need about how to measure your new bike, so it’s sure to be just what you need.

Use this road bike size chart to determine your ideal size. If you choose the correct size road bike, you’ll be more comfortable and efficient, which means you’ll be able to go faster, especially over longer distances.

How are bikes sized?

Bike sizes are based on the distance between the center of the bottom bracket (a metal cup in which the crankset fits) and the top of the seat tube (the frame that holds the seat). The frame size of adult bicycles is used to determine their size. The frame is now measured from the center of the crank axle to most manufacturers’ top of the seat tube. Mountain bikes are usually measured in inches, but most road cycles are measured in centimeters (cm) (in).

Smaller frames are generally associated with racing bikes meant for performance, while larger frames are typically used by people looking for a more comfortable ride. In general, men’s road bikes smaller than 54 cm have a sloping top tube shorter than the average arm span, while women’s road bikes smaller than 54 cm have a sloping top tube that is longer than the average arm span.

What Should Be Measured?

Fortunately, choosing the correct size bikes is easier than it would seem. The equation is simple: standover height X inseam = bike size. This equation is, of course, based on the assumption that you are buying a new bike that fits your body properly.

Height And Inside Leg

Your height and inside leg are the two most important dimensions to take when sizing a bike (inseam). Remove your shoes and stand straight against a wall to measure your height. Make a small pencil mark on the wall level with the top of your head, then measure the height of the mark off the ground with a measuring tape.

Standing with your legs about shoulder-width apart and your shoes off, measure from the ground up into your groin. You can also mark your inside leg on a wall with a pencil and measure it afterward.

Your inside leg measurement is measured to confirm that your bike’s standover height is sufficient. The distance between the top tube of the bike frame and the ground is known as the standover height. A minimum of 1 inch of room between the top tube and your inside leg is advised.

Stand Over Height

Standover height is the distance between the top tube of the bike and your crotch. This measurement is very important for both comfort and safety reasons. Your legs should be fully extended when on the saddle; for some riders, this means they’ll need a larger frame to let them do this comfortably (without their heels coming off the back of the pedals). Conversely, if your legs are short, you’ll likely need a smaller frame to help prevent the pedal strike.

Inseam Measurement

For the most part, bike sizes are based on inches. If you know your inseam measurement, then finding the right bike size should be pretty straightforward. However, keep in mind that Mountain bikes and hybrid bikes tend to be sized by seat tube length (ST) while road bikes are sized by top tube (TT) length.

The Right Bike for You

If you’re buying a bike online or in-person without trying it out first, make sure to head into the store with some solid information about what’s the right size for you. If you have a bike from the same manufacturer, they will likely have the right size in stock and let you try it before buying. If not, don’t be afraid to ask: most people are pretty nice and will happily help you out.

How Does Frame Size Relate to Comfort?

Frame size also indicates the appropriate seat height. A bike that fits you well will have a seat height that allows your leg to comfortably extend while seated on the saddle without leaning forward or backward. The distance from the bottom bracket to the ground is usually about 1 inch shorter than the distance from the bottom bracket to the top of the seat tube.

Learn More About Choosing a Road Bike

Choose an upright position for endurance, so your hands are slightly higher than your shoulders, and go with a longer stem. This will help you avoid neck and back pain since it puts less weight on your arms and torso. A shorter stem will also help you use more of your bike’s handlebars, the preferred position for most cyclists.

If you are sitting on the bike at a complete stop, use a slightly longer stem. The taller your frame is, the longer your reach needs to be. If you are sitting at a complete stop with one leg extended before taking off, make sure you extend another leg out to keep yourself under control because it can be difficult to move forward or backward once you have started moving.

Now, if you want to ride quickly over long distances, try a more upright position with your hands higher than your shoulders and a shorter stem. This allows you to go faster and farther because the reduced leverage will be less strenuous on your body.

If you ride on roads with varied terrain, make sure to choose a bike with a more upright position and longer stem since this will help you maintain control of the bike. If you ride for speed on flat surfaces without sudden stops or turns, it is better to have an aggressive riding position that keeps your body lower over the bike. This allows you to go faster without being as tired because it takes less energy to ride that way.


Most experts advise against purchasing a large-framed road bike because they will have trouble controlling the bicycle, increasing the risk of injury. For most cyclists, the most comfortable position is using a good fit with short stems and an upright position. In general, it is best to choose a longer stem if you are tall and use a shorter stem if you are shorter. You can also play around with different lengths of the stem to find what feels natural for you – for example, between 76 – 96 mm – but it is important to keep in mind that you should not be “forward” leaning so your head rests on the handlebars.