What Size Bike Do I Need? The Ultimate Guide to Using a Bike Size Chart

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When buying a new bike, regardless of the type, it’s crucial you get the correct size for you and your situation. Failing to do so can make riding uncomfortable and a lot less fun and can even lead to injury. Ideally, it’s best to work with a professional bike fitter. However, when that’s not possible, the next best thing is to use a bike size chart.

In the sections that follow, we’ve put together bike size charts for road, mountain, hybrid, and kid’s bikes. Although there’s no such thing as a universal bike size chart that covers all brands and types of bikes, the charts below will provide you with a solid starting point. 

Additionally, although some brands offer women-specific models, there isn’t a significant difference in size between them and standard models. Because of this, both men and women can use the same bike size charts to find their correct bike size.

How To Use a Bike Size Chart

To use the bike size charts below, you’ll need your height and inseam measurements. Knowing both is crucial when choosing the correct bike size. Although you probably know your height, there’s a good chance the measurement includes you wearing shoes. Before proceeding, make sure you get an accurate height measurement with your shoes off.

As for your inseam, it’s important to note that the inseam measurement for choosing the correct bike size differs from the inseam measurement used when tailoring a pair of pants. Here’s a quick and easy method for finding your inseam:

  • Take your shoes off and stand with your back to the wall.
  • Place a book approximately an inch (2.5 cm) thick between your legs and pull it up until it’s firmly tucked into your crotch.
  • Make sure the backside of the book is pressed against the wall.
  • Measure from the top of the book to the floor.

Once you have both measurements, it’s time to compare them against the sizing charts for the different bike types below. If the information below ever conflicts with a brand’s sizing guidelines, it’s best to use the specific sizing chart for the brand of bike you’re considering purchasing.

Road Bike Size Chart

Sizes for road bikes are typically shown in centimeters. However, some manufacturers have started using the more consumer-friendly descriptive labeling format (XS-XL) as well.

HeightInseamFrame Size (cm)Frame Size
4’10″ – 5’0″
148 – 152 cm
27″ – 29″
69 – 74 cm
47 – 48XXS
5’0″ – 5’3″
152 – 160 cm
29″ – 30″
73 – 77 cm
49 – 50XS
5’3″ – 5’6″
160 – 168 cm
30″ – 31″
76 – 79 cm
51 – 53S
5’6″ – 5’9″
168 – 175 cm
31″ – 32″
78 – 82 cm
54 – 55M
5’9″ – 6’0”
175 – 183 cm
32″ – 34″
81 – 87 cm
56 – 58L
6’0″ – 6’3″
183 – 191 cm
34″ – 35″
86 – 90 cm
58 – 60XL
6’3″ – 6’6″
191 – 198 cm
35″ – 36″
89 – 93 cm
61 – 63XXL
**This Road Bike Size Chart can also be used for touring, cyclocross, and gravel bikes.

Mountain Bike Size Chart

Sizes for mountain bikes are either shown in inches or in the more consumer-friendly descriptive labeling format (XS-XL).

HeightInseamFrame Size (in)Frame Size
4’9″ – 5’1″
145 – 155 cm
27″ – 29″
69 – 73 cm
13” – 14”XS
5’1″ – 5’5″
155 – 165 cm
29″ – 31″
74 – 78 cm
15” – 16”S
5’5″ – 5’9″
165 – 176 cm
31″ – 33″
79 – 83 cm
17” – 18”M
5’8″ – 5’11”
173 – 180 cm
32″ – 34″
81 – 86 cm
18” – 19”M/L
5’10” – 6’2″
177 – 188 cm
33″ – 35″
84 – 89 cm
19” – 20”L
6’2″ – 6’5″
188 – 195 cm
35″ – 36″
89 – 91 cm
21” – 22”XL
6’5″ – 6’8″
195 – 203 cm
36″ – 38″
91 – 97 cm
23” – 24”XXL
**This Mountain Bike Size Chart can also be used for hardtail, full suspension, and fat tire bikes.

Hybrid Bike Size Chart

Sizes for hybrid bikes are usually shown in the more consumer-friendly descriptive labeling format (XS-XL). However, you may still find some manufacturers that use centimeters or inches to define their sizing.

HeightInseamFrame Size (in)Frame Size (cm)Frame Size
4’10” – 5’1”
147 – 155 cm
27” – 29”
69 – 73 cm
13″ – 14″33 – 37XS
5’1” – 5’5”
155 – 165 cm
28” – 31”
72 – 78 cm
15″ – 16″38 – 42S
5’5” – 5’9”
165 – 175 cm
30” – 33”
77 – 83 cm
17″ – 18″43 – 47M
5’9” – 6’1”
175 – 186 cm
32” – 35”
82 – 88 cm
19″ – 20″48 – 52L
6’1” – 6’6”
186 – 197 cm
34” – 37”
87 – 93 cm
21″ – 22″53 – 57XL
6’6” – 6’8”
197 – 203 cm
36” – 38″
92 – 96 cm
23″ – 25″58 – 61XXL

Kids Bike Size Chart

Sizes for kid’s bikes are shown in inches and based on wheel size. A 12-inch bike has 12-inch wheels, a 16-inch bike has 16-inch wheels, and so on.

AgeHeightFrame Size
2 – 42’10” – 3’4”
86 – 102 cm
12” Wheel
4 – 63’3” – 3’10”
99 – 117 cm
16” Wheel
6 – 83’9” – 4’4”
114 – 132 cm
20” Wheel
8 – 124’3” – 4’11”
130 – 150 cm
24” Wheel
12+4’10” – 5’3”
146 – 160 cm
26” Wheel

How To Check if a Bike Is the Correct Size

Even after using the bike size charts above, how can you know for sure you have the correct size? Before purchasing a new bike, it’s always wise to double-check. There are three sizing elements you’ll want to test.

Standover Height

Standover height is essentially the distance between the ground and the top tube. It’s important to have some clearance between your crotch and the top tube when hopping off the bike. For most bikes, you’ll want 1-2 inches of standover room for a comfortable fit. When checking the standover height, make sure to wear the shoes you regularly cycle in to get an accurate indicator of the bike’s size.

Leg Extension

When pedaling, you don’t want to feel like you’re reaching, nor do you want your knees coming up into your chest. Both scenarios are uncomfortable, inefficient, and hard on your joints. Ideally, you should have a slight bend in your knee at the bottom of each pedal stroke. Adjust the seat until it feels like it’s at the correct height. If the seat’s at its max height and your legs are still bent, you probably need a bigger bike size.


As the name implies, a bike’s reach is how far you have to reach to grab the handlebars. Unlike standover height and leg extension, there isn’t a “correct” degree of reach. The reach you ultimately settle on will depend on how it feels and the type of riding you plan to do. As a general rule, the longer the reach, the more aggressive and uncomfortable the riding position. The shorter the reach, the more upright and comfortable the riding position.

What To Do if You’re Between Bike Sizes

Because people come in all different shapes and sizes, it’s not uncommon to find yourself between sizes on a bike. So how do you know whether to size up or size down?

When it comes to sizing up, a larger bike will give you a more comfortable upright riding position and can be better for individuals with disproportionately sized limbs. As for the downside, a larger bike is harder to control. There’s also very little you can do to make it smaller, which means adjusting it to a rider’s needs is more difficult.

When it comes to sizing down, a smaller bike will be easier to handle, provide more control, and in most cases, be more fun to ride. You can also do things to make it bigger, such as adjusting the saddle height, handlebar reach, and stem length. Conversely, a smaller bike can be less comfortable and require more rider flexibility.

If you’re unsure which direction to go, it can help to consult with an experienced bike fitting professional. That being said, if you’re between sizes, the general rule of thumb is to size down.

What To Do if You Purchased the Wrong Size Bike

You should probably just suck it up and deal with it, right? Wrong! The last thing you want to do is ride the wrong size bike. Not only is having the correct size bike important for ensuring comfort while riding, but it also helps prevent injury.

Anytime you put your body in an unfamiliar position, it’s going to feel awkward. But that doesn’t necessarily mean you have the wrong bike size or setup. Sometimes your body just needs a little time to adjust to the new position. Try riding the bike a few times and see how it feels. If it still doesn’t feel right or you’re experiencing pain, the next step is to reach out to a professional bike fitter.

Most local bike shops have someone who has experience working on and setting up bikes. They can provide helpful insight into what may be causing the discomfort. It can often be simple adjustments such as moving your saddle forward or backward, adding a longer or shorter stem, or changing your seat post.

If, after trying all of the above, it still doesn’t feel right or you’re experiencing pain, reach out to the store (local or online) that you purchased it from. Most bike brands and stores have flexible return policies and will gladly help you return the bike and replace it with one that fits properly.

Next Steps

Now that you understand how to use a bike size chart and why it’s important to make sure you’re always riding the correct size bike for you, you’re ready to take the next step. Check out our buying guides for bikes, and we’ll help you get one step closer to finding the perfect bike!

Frequently Asked Questions

What additional factors should I consider when choosing a bike based on a size chart?

In addition to the measurements on a bike size chart, when choosing a bike, it’s important to consider factors such as your experience and skill level, the type of riding you’ll be doing, and the terrain you’ll be riding on. These factors can influence the desired fit and feel of the bike, so it’s important to choose a bike that’s well-suited for your specific needs.

Can I still ride a bike if it doesn’t fit me perfectly?

Yes, but it’s not ideal. While it’s always recommended to choose a bike that fits you properly, it is possible to make minor adjustments when it’s not the correct size. However, if the bike is significantly too large or too small, it can be difficult or unsafe to ride even after adjustments are made. A bike that’s too small can feel cramped and put excessive pressure on your knees, while a bike that’s too big can be difficult to control and cause strain on your neck and back.

Should I consult a professional before buying a bike based on a size chart?

While it’s not necessary to consult a professional before buying a bike based on a bike size chart, it can be helpful to get a second opinion from a local bike shop or professional bike fitter. They can typically offer valuable insights on fit and size. They’ll also be able to provide recommendations on specific brands and models that may be better suited for your needs.

Can I use a bike fit calculator to find my correct bike size?

A bike fit calculator is another great alternative. It’s often more reliable than a bike size chart because it takes additional measurements into consideration. The other nice benefit is bike fit calculators are extremely easy to use. All you have to do is key in your measurements and click submit. Two great options are the Jenson USA and Competitive Cyclist bike fit calculators.

Do I need a bike fit if I purchased the correct bike size?

The goal of a bike fit is to optimize the rider’s position so that it maximizes comfort, efficiency, and performance while at the same time preventing injuries. The ideal riding position will vary from person to person (even for individuals who share the same bike size) and can be impacted by factors such as physical characteristics, riding style, and even cycling goals. Whether done by a professional fitter or on your own, making sure your bike is set up and fits you properly is extremely important.

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Hey there! I'm Michael, founder and chief editor of Bicycle Review Guru. I've been an endurance sports junkie the majority of my adult life and fell in love with the sport of cycling when training for my first Half Ironman triathlon over 10 years ago. My passion is sharing my knowledge and expertise to help you get the most out of your cycling journey.

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