How do I know what size bike to buy?

Last Updated: April 9th, 2024

When it comes time to buy a new bike, one of the most important things to do is choose the right size. Having the right, or wrong, size bike can make or break someone’s experience, and for beginners, this can be a challenging process! Luckily, we have some basic guidelines to help you through this.

There are quite a few factors that go into choosing the right size: the rider’s level of experience, the kind of bike being purchased, and above all, personal preference, as everyone will have different fit attributes that suit various riding styles. Most brands have sizing guides available on their websites that are based on height, and these can be a great point of reference when determining where to start before going to test ride a bike.

If you’re buying a mountain bike, please refer to the chart below to get a good starting point for size: 

Rider Height

4'8" - 5'1"

5'1" - 5'5"

5'5" - 5'9"

5'9" - 6'1"

6'1" - 6'4"

6'4" and up

Frame Size







You may have noticed that most sizes have an overlap. This is where your personal preference and individual body proportions come into play. If your legs are short relative to your torso, you’ll likely want to default to the smaller size. Conversely, if your legs are long for your height, you’ll probably want to go with the larger bike. Another thing to consider when choosing between sizes is that a larger bike will feel more planted and stable, while a smaller bike will be more maneuverable and snappy. The important thing to remember, though, is this: it’s easier to make a smaller bike fit larger than it is to make a larger bike fit smaller.

If you’re buying a road or gravel bike, refer to the chart below:

Rider Height

5'2" - 5'6"

5'5" - 5'9"

5'7" - 5'11"

5'9" - 6'1"

6'0" - 6'4"

6'3" and up

Frame Size







Once again, you probably noticed some overlap. Just like with mountain bikes, this aspect will ultimately come down to personal preference, how you intend to ride the bike, or it may even depend on specific manufacturers.

Hopefully, this has provided you with a general starting point for finding the bike that will best fit you and your intentions. It's worth noting that some brands may have different sizing conventions than others. In such cases, we recommend checking out their specific size charts.  

Still Need Help?

Purchasing a bicycle online is a substantial investment and costly to ship. If you have any questions or reservations prior to your purchase, feel free to give us a call at 866-600-2453, send us an email at, or visit your local Mike’s Bikes! It is always far more cost-effective for all parties to address technical or sizing questions prior to purchase rather than after.