There are many different tire sizes for bicycles, but that's not all – there are also different size-systems. With this blog article, we want to provide you with a quick and easy overview and help you find the right size for your bicycle.
In addition to various tips for choosing the right tires, you will also find a clear table of bicycle tire sizes in all common size specifications.
What size systems are there?
Bicycle tires (or “covers”) are divided into different size systems:
- In inches
- There are also the ETRTO values
- And the French size specifications.
For a better overview of tire sizes, we have created a table where you can find the different specifications. It is important to know that inches refer to the diameter of the tire, while French sizes and ETRTO specifications directly indicate the combination of diameter and width.
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Attention, besides the tire size, the selection of the appropriate tire width also plays an important role! You can find more information in our article "Find the right tire width for your bicycle". |
In our table, you will also find the recommendations for combinations of tire width and rim width (“rim mouth width”), which you need when you want to buy new tires for your bicycle that are wider or narrower than the existing ones.
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Important: You can find the size of your bicycle tires on the sidewall of the tire (there's a picture of it further down). |
Table: Overview of common bicycle tire sizes
The common tire sizes on bicycles in inches
Tire sizes on bicycles are often given in inches. Especially with manufacturers from the USA, you will also find the English term Inch. Especially with mountain bikes, children's bikes, trekking bikes, and many city bikes, the wheels are measured in inches or inch.
- Inches are a common size for MTBs, children's bikes, trekking bikes, and city bikes
- Inch is the English term for inches
- Inches can be abbreviated with “, for example, you will often come across terms like 26”-bicycle in product descriptions.
- Attention! A 24-inch bicycle has 24” wheels, but the size is used in this case as a representative for the entire bike!
The following common sizes are usually found in inches:
12 - 24" inches
These tire sizes appear primarily on children's bikes and balance bikes. Occasionally, you can also find them on folding bikes or recumbent bikes. Compact bikes often have 20", which also applies to compact e-bikes.
26" Inch
This size was long the common size in the MTB sector and is still occasionally available today. You often find them especially on bikes for teenagers. At 26", it also marks the transition from children's bike to adult bike.
27.5" Inch
27.5" tires have largely replaced the old 26" tire standard in the enduro, all-mountain, trail, freeride, and downhill sectors. 27.5-inch wheels skillfully balance propulsion and playful handling.
28" Inch
For city, trekking, and touring bikes, 28-inch bicycle tires are the standard. Likewise, road bikes and gravel bikes are mostly equipped with them (but they are not measured in inches).
29" Inch
These tires are mainly found in the marathon and XC sectors, but they are also increasingly seen on enduro and all-mountain bikes. Due to their large circumference, they roll much better over obstacles, but in return, they are not quite as playful as smaller tires. Occasionally, this tire size can now also be found on downhill bikes.
Here, in addition to the size of the bicycle tire, you can also read the manufacturer's recommended air pressure (PSI indication).
Bicycle Tire Size Classification According to ETRTO
In addition to the usual size indication in inches, the size classification according to ETRTO (=European Tire and Rim Technical Organization) is still used. Here, the tire width followed by the tire inner diameter - each in millimeters - is specified. The tire inner diameter also indicates the nominal diameter of the rim on which the tire can be mounted. So if you have a tire with the ETRTO size 37-559, it is 37 mm wide and has 559 mm in diameter (inside). The rim must then also be 559 mm in diameter.
ETRTO and the Rim Width
There are also recommendations for combinations of tire width and rim width. The width of the rim - also called the rim width - determines which tire width can be mounted.
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A tire that does not fit the rim can, at worst, lead to damage and unfavorable handling. |
- An extremely wide tire should, for example, not be mounted on a very narrow rim.
- Likewise, no tire can be mounted that is too narrow or even narrower than the rim itself.
French Tire Sizes
Another size classification for bicycle tires is the French designation.
French sizes are mainly found in road bike tires, but these tire sizes are also specified for some gravel bikes. An example would be the size 700 x 35C. Here, the three-digit number indicates the approximate outer diameter of the tire, the two-digit number indicates the tire width, and the letter stands for the tire's inner diameter or rim diameter. It may seem a bit complicated at first, but a look at our table shows you the actual size of the tire.
Besides the tire size and width, the tire profile greatly influences a bike's handling!
Finding the right tire size... here's how to do it
Finding the right bicycle tire is not that difficult.
With a bit of luck, you will find a size and rim width specification on the rim; here 26 inches and 25mm. Then you can easily buy the right tires. Image © DT Swiss
Option 1:
- If you just want to replace a worn-out tire, you can look for the size on the sidewall of the old tire and order a new tire in the same size.
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For most bicycles, you have to stick to the tire size they were built for. You can only change the tire widths. |
Option 2:
- If you want to test slightly wider or narrower tires, you should know the rim width of your rims. Our table then helps you select the possible tire widths.
- In addition, you need to know how much tire width your bike frame allows.
- You can then choose the right tire for your bike from different tire widths in the appropriate diameter.
🔺Buy the right bicycle tires🔺
Wire tires | Tubeless tires | Tube tires | Spike tires | Children's tires
You can find much more information in the other parts of our tire series:
- Find the right tire width for your bicycle
- How to convert your MTB to tubeless
- Everything you need to know about bicycle valves
- Gravel tires – what you should know!
- E-Bike tires – useful or useless?
