how to measure bike wheel size

How to Measure Bike Wheel Size: An Easy Guide for Beginners

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What size bike wheel should you buy for your new bike? That depends on the frame size of your bicycle. You need to know that it is crucial to have a matching set of wheels and tires compatible with your riding style.

In this article, we will provide some tips on how to measure bike wheel size so that when it comes time for purchasing new tires, parts, or accessories, you can make sure you get what fits!

Bike Tire Sizing Systems Explained

Conventional Sizing Method

The traditional sizing method, which is based on the outer wheel diameter measurement, is a conventional system for measuring bicycle tires. This has been in use since the 1800s.

In this method, a ’27 inch’ tire is approximately 27 inches from one side to the other when measured along its outer circumference.

However, there are many different manufacturers for tires and rims – making it difficult sometimes to get a perfect match! This can mean that the size of the tire you choose may not be exactly as it appears.


A more modern method for measuring bike wheel size is known as ETRTO sizing. This was first introduced by the European Tyre and Rim Technical Organisation in 1990.

This new standard uses an inner rim diameter measurement to define the tire’s width and height, which reduces the chance of any confusion.

ETRTO sizing is now the official industry standard for all tire manufacturers, whether they are European or North American. The ETRTO system calculates measurements based on inner edge dimensions with a tolerance of 0.05mm (0.002 inches). This means that you will always get what you expect when buying bike parts.

With the ETRTO system, any tire that has an internal rim wheel diameter of 15 to 25 inches will be measured in millimeters (mm). If your bicycle measures up with an inner rim size of 14-24 inches, you should use tires that are printed in this fractional/decimal format: 54-584 or 57-584.


ISO bike tire sizing is developed by the International Standards Organisation and is used mainly in North America. This system also uses the outside diameter of a tire to calculate its width and height measurements.

The ISO system calculates measurements based on an internal rim size with a tolerance of 0.15mm (0.006 inches). The only difference between this measurement standard and ETRTO is the tolerance of 0.15mm (0.006 inches), which is wider than ETRTO’s maximum of 0.05 mm (0.002inches).

To use this sizing method, you need to know that tire widths are given in millimeters, and heights can be measured as a ratio relative to their widths – such as 60% or 80%. This percentage refers to how wide the tire is in relation to its height.

For example, a 200mm x 50mm ISO-rated road bike tire will be 100 mm high (50% of 200mm), while an 80/90 B18 ISO mountain bike tire will measure exactly 180 millimeters when inflated.

How to Measure Bike Wheel Size: Step-by-Step Instructions

Knowing the size of your bike’s wheel is important when you are buying a new bike. You want to make sure that it can handle all types of terrains and weather conditions, whether in town or on-road biking adventures. Here’s how to measure bicycle tire size:

Step 1: Position Your Bike Upright With Tires Touching the Ground

This is crucial to get the tire’s measurements without any difficulty. You can lean your bicycle on the wall or use the kickstand for stability and for more accurate measurements.

Step 2: Measure Your Tire’s Diameter

Using a measuring tape or a retractable metal tape, measure the distance from the middle of the wheel to the edge of the tire. This is the wheel’s radius.

Next, multiply the measurement by two to get an accurate measurement of the diameter of the tire. Most wheels are between 26 inches and 29 inches.

Step 3: Measure the Width of Your Bicycle Tire

You can use a measuring tape or a ruler to get the tire width. Just make sure that you do not measure part of your brake system, which may affect its size.

The tire width depends on the type of bicycle you have. For standard bikes, it is usually about one inch wider than the tire diameter measurement.

For road bikes, this should be narrower by a few millimeters compared to your tire’s width or circumference size.

Note that BMX models for children will always have smaller wheels and thinner tires because their diameter is usually smaller than that of standard or road bikes.

Step 4: Calculate the Circumference

Combining the bicycle wheel diameter and width will give you the wheel’s circumference.

The circumference of a wheel is the distance traveled by the bicycle’s wheel in one rotation. The circumference of your tire directly affects how quickly or slowly you can get to your destination.

For calculating the circumference, you need to multiply the width by 3.65.

So if your bike tire is 26 inches, its circumference will be approximately 97cm or 38 inches. This means that it has a low speed for trails and paths but can handle bumpy roads well.

For road biking, your bike’s circumference should be around 80cm or 31 inches. This is the median speed for paved roads and trails with light barriers like railings.

BMX bikes usually have smaller circumference measurements of 20-26 inches, while children’s bikes will go down to about 19 inches or less. The lower limit is 14inches, which is suitable for children aged four to six years old.

Bike Wheel Sizes Explained

Teenage boy and his father looking for new wheel cover for sport bike in store

Knowing the right size of your bicycle’s wheel is essential for biking safety. If you are not sure which one to buy, here’s a quick guide on how they differ:

20-Inch Wheels

These wheels are ideal for bikes for children aged four to six years old. Bicycles with this wheel size can be used on paved roads as well as off-road trails with minor barriers like grass, sand, or dirt. This type is also very light, so it’s easy to transport around.

26-Inch Wheels

These fit most types of bikes for hybrid and mountain bikes. They can be used in paved roads as well as off-road trails with moderate barriers. This mountain bike tire size also provides a medium speed and can handle small obstacles like stones easily.

27-Inch Wheels

These are usually for road bikes and have a high speed so you can get to your destination quickly. Since 27-inch options are light, some riders find that they don’t do well with rough terrain or steep paths, but this depends on your bike’s frame strength as well. These wheels are usually thinner and have narrow tires than other sizes.

29-Inch Wheels

These are the standard type of bicycle wheels. If you want to purchase one, make sure that your frame is strong enough for it, or else there’s a chance that it might break when used off-road. These bicycle wheels can handle high speeds, rough roads, gravel paths as well as steep trails.

40-Inch Wheels

These are usually found on BMX bikes for riders to do tricks easily with the bike’s lightweight design. For those who want to use this size off-road, make sure that your frame is very strong so you won’t encounter difficulty moving it around.

Frequently Asked Questions on Bike Tire Sizes

Can I Substitute Mountain Bike Tires With Regular Ones?

No, you cannot substitute mountain bike tires with regular ones.

The difference between mountain bike tires and regular tires is that a mountain bicycle tire’s tread allows for better traction on terrains like mud or sand. The wheels of road bikes are thinner and have smoother and narrower treads compared to mountain bike wheels.

For mountain bike wheels, you can choose between 26-inch and 29-inch tires. Your choices may vary greatly depending on your preference in using them for rough or paved roads.

How Do I Know if the Rim Is Suitable for the Tires That I Want?

It’s best to check your current tire size and match it with equivalent bicycle rims. If your old tire size is not a perfect fit, you can always go up or down by two inches, depending on how much you want to change it.

To ensure that your new tire fits perfectly, you must know how to measure a bike rim as well.

Are 29-Inch Wheels Suitable for Urban Cycling?

Yes, this size is very popular in most cities because it can handle rough or paved roads well with its high speed and medium-weight design. Since the tire size is not too big nor small, it provides an adequate balance between speed and control.

What Is a Tire’s Bead Seat Diameter?

The bead diameter is the size of your bicycle wheel rim. You can check the specifications on the sidewall of your tire or looking for it in the manual.

What Is the Difference Between 700c and 28-Inch Wheels?

700c refers to an approximate measurement of a bike’s rim, while 28 inches (or 27.75) indicates its tire size. If you want more speed, go for 29-inch wheels because they will ensure improved control on off-road trails or pavements. 

This type is also preferred for BMX bikes because its lightweight design makes it easier to do stunts. If you want better traction, however, go for 26-inch tires.

What Are the Best Sizes for Bicycle Wheels?

There is no absolute answer to this question, but certain types of bicycles have more demand in the market today, depending on their intended use.

For example, 29-inch wheels are perfect for road bikes because of their high speed, which is essential if you want a faster ride.

On the other hand, 26-inch tires can be used in mountain tracks or even sometimes in urban roads with smaller barriers. These wheels are better for stunts, while 40-inch BMX tires are not recommended to use on paved roads.

What Is the Difference Between the 20-Inch Wheel and 700c?

Twenty-six inches refers to a measurement of a bike’s tire size, which usually has an aggressive tread that allows better traction on rough or muddy paths. 700c, on the other hand, refers to an approximate measurement of a bike’s rim.

For more speed, go for 29-inch tires because they will provide better control on off-road trails or pavements. This size is also preferred for BMX bikes because the lightweight design makes it easier to do stunts.

If you want better traction, however, go for 26-inch tires.

How Does a Mountain Bike Wheel Differ From Road Bike Wheels?

Mountain bikes have wider tires and rims to improve their control on bumpy or muddy paths. You will usually need a 26-inch mountain bike tire for this type.

Road bikes have high speed and can handle rough roads as well as steep trails. These types of bikes usually use 700c rims, which are thinner than regular ones to achieve this purpose.

What Are BMX Bike Wheels?

BMX bikes, which stands for “bicycle motocross,” usually have 40-inch tires or even larger ones. Their frames also have an aggressive design that allows them to be used for stunts.

What Size Bike Tire Should I Buy?

If you want better control and traction, go for a 26-inch bike tire. If you plan to do stunts on BMX bikes, make sure that the wheel is 40 inches in circumference. Otherwise, a 29-inch tire size will be perfect for those who like speed as it is lightweight and can handle rough or paved roads well.

What Wheel Size Should I Use on My Hybrid?

This will depend on the type of hybrid bicycle you have. If it has drop bars, then 26 inches is usually suitable for use in paved roads and trails with light barriers like railings, whereas 29-inch wheels can handle rougher paths, including gravel.

For flat bar hybrids, go with 26-inch wheels, ideal for use on paved roads and trails with light barriers.

Can I Use a Bigger Wheel on My Bike?

Yes, you can definitely choose to use larger wheels which are usually 29 inches or higher but make sure that your frame is strong enough for it because using the wrong size can cause damage to your bike’s components, especially if they are not compatible.

A 29-inch wheel is usually for road bikes and has a high speed so you can get to your destination quickly.

How Do You Measure a Bike’s Tire Size Accurately?

If you’re wondering, “what size is my bike tire?” there are many ways to accurately measure your bike’s tire size depending on the type you have. You can use a ruler or even buy an actual tool that measures wheel sizes to ensure compatibility with your tires.

Can I Use a Bicycle Wheel Circumference Chart?

Yes, you can use a circumference chart! The easiest way to measure your tire’s size is by using the circumference method. You will need something that measures in feet or inches so keep that in mind when choosing an appropriate tool. You can also find a bike wheel size calculator online if you need one.

Choose the Right Bike Wheel Size

The size of the wheel is one of the most significant factors to consider when purchasing a bicycle. Choosing the right wheel size for your bicycle is essential to ensure it has proper control and traction on different types of terrain.

We have provided tips about determining what type of wheel you need based on your intended use and how to tell bicycle tire size. In addition, we have included the benefits of standard wheel sizes like 26-inch and 29-inch wheels.

Now that you know how to measure bike wheel size, you can carefully consider your options before purchasing a new tire or wheel. You’re now assured that your bike can handle different types of terrains and weather conditions, whether in town or on the road.

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