A Guide To Understand Truck Tyre Size

For the sake of vehicle, safe transportation and smooth driving, understanding truck tyre size is important. It’s obvious that buses and trucks carry thousands of pounds therefore tyres must be chosen correctly to ensure optimum safety and it also impact the transmission gearing mechanism as well as road speed. Have a look at the details below to understand truck tyre before choosing one!


A standard formula is applied with the truck wheels. A typical tyre profile would look like 11R22.5G whereas low-profile alphanumeric will appear something as 275/80R22.5G. Aspect ratio and section width is represented by the 11 and 275/80 with “R” for radial tyres.

Note: Cross-ply truck tyre will have a dash (-) between the alphabet and the following digit.

“G” is the load rating whereas 22.5 highlight the wheel diameter. It must be noted that section width is the widest point of an unloaded tyre and section height is the distance from the wheel rim all the way to the tyre exterior.

Aspect ratios

Truck tyre sizes that begin with the digits 8, 9, 10, 11 and 12 are customary profiles of tubeless wheels with body width mentioned in inches. Aspect ratio of standard tyres is usually 88 percent that defines the height from rim to the tread bearing 88 percent width.

Likewise, an 11R22.5 tyre is approximately 11 inches in diameter and around 9.5 inches in height. On the contrary, low profile tyres represent width in millimetres such as 275/80R22.5; here, 275 is the diameter in millimetre and 220 is the height in same unit of measurement.

Low aspect tyre ratios for truck can be 70, 75 and 80 percent whereas width for tube-type wheels is given as 9.00, 10.00 or 11.00. Take example of 1000R20 that’s pronounced “ten hundredth and R twentieth”. Aspect ratio of 98 percent is maintained in tyres that require inner tubes.

The wheels

Size of the wheel explains a lot about the tyre as all represents the wheel diameter in inches. Whole-number size indicates multi-component wheels requiring an inner tube.

Tube wheel sizes are commonly 20 to 24 inches whereas half-inch dimension is for tubeless truck tyres. It can be something like 19.5, 22.5 or 24.5 so on.

Wheels for trucks come in many different widths but to make sure you get the proper fit, consult the tyre size chart to compare size and wheel width.

Load range

How much weight a tyre can withstand is indicated through the final letter in the tyre size which is also known as the load range. Take example of “G” from 11R22.5 and lower profile 22.5 that explains the supporting weight is nearly 2801 in kilogram with an inflation of 105 PSI in a single tyre application.

In contrast, dual mounted tyres have a lower load rating whereas load capacity also fluctuates at different inflation pressures. Your tyre manufacturer is likely to explain all the significant facts through a chart. Front axle of dumpers and cement mixers bears an “L” indicating they can easily carry a load above 5443 kilogram per the tyre.


The technical details above are to explain different tyres and their features so you may get the right one for your truck.