Bikes have a lot of parts that make them up, but two of the most important are the bike wheel and the frame. The wheel is bolted to the frame in order to keep your bike upright and roll along when you pedal. The size wheel you will need largely depends on the frame size. To measure your bicycle wheel size, just follow these steps:

What Is My Wheel Size?

This is the most common question we get asked here at Easi-Fit E-Bike Kits. You don’t need to worry about bike wheel sizes too much, as we offer the kit in many different sizes and for any type of bike too. That’s right, any bike from a mountain bike, road bike, travelling bike, folding bike, commuter bike, three-wheeled bike and more. We accommodate large wheels, smaller wheels, everything in between and it doesn’t matter whether you have a new bike or an old bike. You can always give us a call if you struggle to check your bicycle wheel size.

Different bikes tend to be measured with different metrics. You will notice that road bike tyres tend to be measured in metric units while mountain bike tyres often use imperial units.

For example, a road bike may read 700 X 23C. A mountain bike wheel size measured in imperial units may read as 27.5 X 2.3

Most adult bikes and common bicycle wheel size (with the exception of folding bikes) have a standard ETRTO 622 wheel (28″/29″/700C). However, as a keen cyclist you will need to find out your exact size easily, here’s how you can:

Check Tyre Markings

Not all wheels are the same size so you’ll need to check the markings on your tyres.  The image below shows you where to find this number. This is the best and easiest way to identify your wheel size.

Wheel sizes have been measured in a variety of guides for some time now. Some measure our wheel sizes by ETRTO number, a 5-digit number of the form ## – ### which tells you the precise diameter. The first two digits of the ETRTO are the tyre width in mm. The last three are the inner tyre diameter.

You may find you have the French measures which will be displayed as a number followed by a “C”. Or if you have English tyre markings you may see an X in between the two sets of numbers such as diameter X width. You can view how these may appear on the visual below:

Bike Wheel Size Guide

Measure Your Bike Wheel

You can measure your bicycle wheel on a bike without taking it off the frame. Use your tyre width and rim diameter to calculate wheel size:

Measure your bike wheel size in inches

If you’d like to take your measurement in inches rather than using millimetres or centimetres read on.

Step 1: Start by measuring from one side of the centre hole to the outer edge of the tyre and record that number. Then move to the other side and record that number too. Now you have two measurements, if your wheels are the same diameter on both sides then add them together. If they are different diameters then take the larger measurement and subtract it from the smaller one. Now you have your rim diameter, you can move onto width. 

Step 2:  to find out the width, measure the flat surface across the tire’s tread from one side of the tire to the other.

Step 3: Combine the measurements of tire diameter and width to reveal the tire size. Traditional bike tire sizes place the diameter first and the width second. 

Standard tire sizes are in full-inch increments for the diameter. If you are slightly over or under, round to the nearest inch.

Measure your bike wheel size in ETRTO

Step 1: The easiest way to do this is to put a tape measure from the centre of the wheel to the tyre’s inner edge where it meets with the rim. 

Step 2:  Make a note of this measurement in mm. This is the inner radius of the tyre.

Step 3: Multiply this number (R) by 2. You now have the diameter of the rim. [E.g. 317×2 = 634mm]

Step 3) Subtract 10mm from the diameter. [E.g. 634-10 = 624mm] 

Step 4) Match your measurement with the nearest wheel size in the table above – it should come within ±3mm. E.g. 624mm = 622

You then want to run that tape measure along the tyre, start by measuring from one side of the centre hole and record that number. Then move to the other side and record that number too. Now you have two measurements, add them together and your wheel size will be revealed.

Check The Bike Manual

Your wheel size often can be found within the manual that came with the bike. If you didn’t buy the bike that long ago, you can contact the bike shop where you bought your bike and they will be able to tell you the metrics you need.

You can also check the bike details on the retailer’s website, the information you need is often in the specifications section.

Still can’t find it? Contact Us

If you wondering what size are my wheels? please call us on 0333 577 0343. Alternatively, you can email us a picture of the writing on your tyre to 

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