Tire Size Calculator - Compare Tire Dimensions.See how new tires and rims will look on your car or truck. We’ll help you make the right choice about the tires and wheels for your vehicle’s suspension, gearing, and bodywork. If you’re considering mounting a different tire size on your vehicle, stop by Les Schwab. Tires that are the wrong size could cause some pull in the steering wheel, rub against the suspension or body of your vehicle, reduce clearance on hills, or result in a stiffer or noisier ride. It’s important to stay within the sizing tolerances of your vehicle. But remember, this calculator is only an estimate. above 186 mph, a ZR must appear in the size designation, including a Y speed symbol in brackets.īuying New Wheels or Changing Your Tire Size?Ī tire size calculator is a quick way to ensure a new set of tires will fit your car, SUV, sports car, light truck or crossover.

*For tires having a maximum speed capability above 149 mph, a ZR may appear in the size designation. Tire Size Chartsīelow you will find several charts that will help you understand tire sizing numbers, including a load index chart and speed rating chart. (Of course, you should always abide by speed limits for safer driving.) Speed rating is usually, but not always, a single letter (see the chart below). The maximum operating speed of a vehicle is no more than the lowest speed rating of all tires mounted on the vehicle. A tire with a higher speed rating can handle heat better and provide more control at faster speeds. This indicates the top speed it’s safe to travel for a sustained amount of time. The last letter is the tire speed rating. Please note: Some run-flat tires are identified with an F followed by the type of internal construction. This means the tire has a load capacity of 1,279 pounds, when inflated to the tire’s maximum air pressure rating. The load index symbol indicates how much weight a tire can support, based on the following standard chart (see below). The two-digit or three-digit number that follows the gap specifies tire load index. It’s the distance between the two bead seat areas (where a tire gets tightly sealed onto the wheel). This two-digit number specifies wheel diameter in inches. Some motorcycle and trailer tires still use this internal construction. They are also called conventional, x-ply, or cross-ply tires. D: Diagonal Plies or Bias-Constructed Tiresĭ is for tires built with diagonal (crisscrossed) plies, called bias-constructed tires. In a radial tire, the plies - layers of strong cords made of a blend of polyester, steel and fabric and coated with rubber - are laid perpendicular to the direction of travel. They have better road grip, lower rolling resistance for better gas mileage or electric range, ride comfort and durability than previous generations of tires. R is for radial tires, the industry standard for most tires today. This single letter tells you about the internal construction of the tire. This gives you an answer of 5.5, the sidewall height in inches. To get the sidewall height, take the tire width of 215 mm and convert it to inches (8.46). In this example, the aspect ratio is 65, meaning the sidewall is 65 percent as high as the tire is wide.

It’s the height of the sidewall measured from wheel rim to top of the tread, expressed as a percentage of tire width. The aspect ratio is indicated on the tire sidewall as a percentage. The bigger the aspect ratio, the higher/taller the tire’s sidewall, or “profile” as it’s sometimes called. The forward slash separates the tire width number from the two-digit aspect ratio. This may also be referred to as the section width. The three-digit number following the letter is the tire’s width (from side to side, looking at the tire head-on) in millimeters. Confused by all the numbers and letters? The pros at Les Schwab can help. It’s also measured in millimeters but may have a different load capacity than a P or LT tire. If there’s no letter before the first number, you have a metric tire most commonly referred to as European size. These tire sizes are meant for trailers, including fifth wheels and other travel trailers, as well as boat and utility trailers. These are often equipped on three-quarter or 1-ton trucks and SUVs. LT means light truck tire, designed for vehicles capable of carrying heavy loads, towing trailers, or for those looking for an extra heavy-duty option.While the right load capacity can be achieved for electric vehicles with a standard passenger vehicle tire, special EV tires may be available for some vehicles. P-class tires include cars, SUVs, crossovers, minivans and smaller pickup trucks, as well as EVs (electric vehicles).

Tire size comparison tool