700x50C Tire Size in Inches – Know the Calculation

In the realm of bicycle tire sizes, the term “700x50C” can be quite perplexing.

While one might assume that 700 corresponds to 27.5 inches and 50 translates to 2 inches, the real calculation is not that straightforward.

If you simply purchase a 27.5 by 2 inches tire for your bike, the compatibility issues will surely lead you to disappointment. 

Randomly selecting a set of tires based on assumptions can result in a misfit, risking tire rub against the frame or fork.

To fully comprehend the implications of a 700x50C tire size, we must dig deeper into the intricacies of tire measurements and their impact on bike performance and safety.

Therefore, read this article to make a precise tire size calculation for your bike.

How to Denote the Bike Tire Sizes?

Representing Bike Tire Sizes

As mentioned earlier, 700x50C is equivalent to 27.5 by 2 inches of tire size. But this measurement is not always accurate. If you think separately, 700 is the tire diameter and 50 is the tire width, in millimeters.

Therefore, if you perform the conversion, the tire size will make sense. But, if you go to a local store and ask for a 27.5 by 2 inches tire size for your bike, it will be compatible with your model of bike.

To understand the right size, one must be familiar with the term ‘C’ denoted in the bike tire size. What does it stand for? Follow the later section to find the answer!

What Does “C” Mean in Bike Tire Sizes?

What Does “C” Mean in Bike Tire Sizes

In bike tire sizes, the “C” represents the bead seat diameter of the tire. The bead seat diameter is the diameter of the rim on which the manufacturers set the tire for firm support. 

The “C” designation is commonly used for road bike and hybrid bike tires, where the bead seat diameter is 622mm.

Road bike tires with a bead seat diameter of 622mm are also referred to as “700C” tires. 

The “700” in “700c” is derived from an older French system of tire sizing, where it represents the approximate overall diameter of the tire in millimeters (as mentioned above).

However, the actual bead seat diameter is 622mm. It is important to note that the “C” designation is specific to road bike tires. Other types of bicycles, such as mountain bikes, use different tire sizing systems with different bead seat diameters and designations.

Calculation of 700x50C Tire Size in Inches

To convert a 700x50C tire size to inches, you need to know the bead seat diameter (BSD) associated with the “C” designation. In the case of road bike tires, the common BSD for 700 tires is 622mm.

With that information, you can convert the tire size to inches using the following formula:

Inch size = (BSD in millimeters + (2 x tire width in millimeters)) / 25.4 

Given a 700x50C tire size, let’s calculate the inch size:

BSD = 622mm

Tire width = 50mm

Inch size = (622 + (2 x 50)) / 25.4

Inch size = (622 + 100) / 25.4

Inch size = 722 / 25.4

Inch size ≈ 28.43

Therefore, a 700x50C tire size is approximately 28.43 inches.

Now, after visiting your local bike store and asking for a tire size of 28.43 inches in diameter, the mechanic will cross-match that size and they can figure out that the equivalent size is 700x50C for your bike model.

Note that if you know the original French size, for example, 700x50C, our suggestion will be to notify the store owner with that information so as not to raise any confusion.

With that being said, the table below will show the respective diameter sizes in inches for all the standard bike tire sizes. Make sure to give it a glance for your betterment.

Tire SizeTire Dimensions (inches)Actual Tire Diameter considering BSD (inches)
700x18C27.5 x 0.7125.94
700x19C27.5 x 0.7526.06
700x20C27.5 x 0.7926.14
700x25C27.5 x 0.9826.38
700x30C27.5 x 1.1826.90
700x35C27.5 x 1.3827.17
700x40C27.5 x 1.5727.57
700x45C27.5 x 1.7728.10
700x50C27.5 x 228.43

How Many CO2 Cartridges Should I Use to Fill My 700x50C Bike Tire?

When it comes to filling a bike tire with co2 cartridges, determining the right amount for a 700x50C tire requires consideration. Generally, one or two cartridges should suffice to achieve optimal tire inflation. However, factors like tire pressure preferences and conditions while riding may influence the number needed. Remember to gauge the appropriate amount to ensure a smooth and safe ride.


1. Can I replace my 700x50C tires with 27.5×2-inch tires?

No, you cannot directly replace 700x50C tires with 27.5×2-inch tires. The two tire sizes have different bead seat diameters and overall dimensions, making them incompatible. It’s important to choose the correct tire size specified for your bike’s requirements.

2. Are wider tires better for road biking?

Wider tires can offer increased comfort and improved traction on rough surfaces. However, for road biking, bikers prefer narrower tires as they provide lower rolling resistance, resulting in better speed and efficiency on smooth pavement.

What is the Conversion Formula for Calculating Tire Size in Inches?

The 700x40c tire size measurement guide provides a simple formula to convert tire sizing to inches. Multiply the tire’s width in millimeters by 0.03937 to obtain the width in inches. Similarly, multiply the tire’s nominal diameter (including the tire height) in millimeters by 0.03937 to get the diameter in inches.


To wrap up, the 700x50C tire size in inches has proven to be a complex and multifaceted subject. While it may be tempting to equate it to 27.5 by 2 inches, a deeper understanding is required to ensure proper fitting and compatibility.

The Bead Seat Diameter (BSD) is a crucial consideration when determining the appropriate tire size for a bike. By understanding the importance of BSD, cyclists can make informed decisions about tire compatibility and avoid potential dangers such as frame or component damage.

Next time you think about buying new tires, make sure to calculate the accurate tire diameter to inform your local bike store owner. Have fun cycling!

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