The Most popular commercial tire sizes

the tire sizes most found in semi trucks are 295/75R22.5, 275/70R22.5, & 225/70R19.5. These are not the only tire sizes found in trucks, but the most common.

The tire sizes always in stock:

295 /75 R22.5

11R22.5.

315/80R22.5

255/70R22.5

The best way to understand the 295/75R22.5 size is to break down the numbers into different categories.

Truck Tire Sizes Explained

Tire Width - The first number in the series shows the tire width. 
Semi-truck tire width can be displayed in terms of inches or millimeters. This image shows a 285-Millimeter. This is where the rubber meets the road.

Aspect Ratio - The second number (35) after the slash mark is the aspect ratio. It represents the percentage of the length of height to width. This number is important for sizing the tire with the rim diameter to help you determine your best tire and wheel combinations. 

Tire Construction Type - the letter R stands for radial (this tells us that the steel belts inside are running 90-degrees from the direction the tire is facing). If you see a dash, the tire is bias-ply (this tells us that the nylon belts running anywhere from 30 to 45-degrees from the direction the tire is facing).

Rim Diameter - The number 19 is the diameter. This does not apply to the diameter of the whole tire, but the semi-truck wheel diameter (the hole in the center of the tire). You would need a 19-inch wheel to fit this tire.

When reading the sidewall, you will encounter two additional numbers.

Load index - This number will indicate how much weight or load carrying capacity a single tire can hold. For example, 82 = 1,047 pounds.

Speed rating - You will see a speed rating letter at the end of the string. This indicates how fast the tire can go under its maximum load. A tire can go faster than this number at a lower load, but typically the tires can withstand a higher speed than the speed limits you will encounter.