# Blog

## What Size Mudflaps do I Need?

There are a couple of different ways to decide which mud flaps you want. It really depends on the size of your tires. Mud flaps are ordered by specifying the width of the tire and the overall diameter of the tire.

On the side of your tires there is a set of numbers, it will either look like 195/70 R 16 or more like 33x10x14. The first is a metric measurement and the second is “standard” or “imperial”.

Imperial Sizing

The imperial system is the easiest case. The width and diameter are expressed in inches which is exactly what we need to order mud flaps from TimberWood Off Road!

Metric Sizing

In the metric measurements, the first number is the width of the tire in millimeters. The second is called an “aspect ratio”. It basically means “how high is the sidewall in comparison to the width of the tire?” The letter R just means that the tire is of radial construction. The last number represents the diameter of the rim that the tire fits. Strangely, in this metric system the diameter is expressed in inches.

So, for metric tires we need to convert the width to inches and calculate the overall diameter of the tire. Fortunately, there is a very easy-to-use calculator here.

If you are really interested in solving for these measurements yourself, here’s how:

Divide the width by 25.4 to give inches. In the example above we divide 195 by 25.4 and find that the tire is 7.68 inches wide. To find the overall tire diameter we have to find the sidewall height, multiply it by two (because you have to consider that there is tire above the rim as well as the bit of tire that the rim is sitting on) and then add the diameter of the rim itself.

So, for the example above : the sidewall is 195mm x 0.55 = 107mm. We multiply 107mm by two and get 214mm. However, we need this measurement in inches so we divide it by 25.4 and find that the combined height of the sidewall above and below the rim is 8.4 inches. Now we just add in the height of the rim itself (16 “) and find out that our tire standing on the pavement is 24.4 inches tall. Those tires are too small for your truck but now you know how to do it!

Now that you know…

So, now that you know the width of your tires and the overall diameter (in inches) you can choose which of TimberWood’s premium quality aluminum mud flaps you need to buy and a enjoy light, good-looking, rust-free product for years to come!

For tires up to and including 33″ in diameter by 11.5″ wide

For tires up to and including 36″ in diameter by 12.5″ wide