Tire size is a very important part of a car’s appearance, as well as safety. There are many factors that go into choosing the right tire size for your car.
There are two ways that tire manufacturers display tire size, inches and metric. How to read tire size in inches is very straightforward.
Example A: 33X12.50R15 The first number is the overall diameter of the tire (the height). In this example, the tire diameter or “height” is 33 inches tall. The second number represents the width of the tire (width).
To find the size of your current tires, look at them in the garage. The back of each tire should have a label showing its diameter.
Table of Contents
How do u know what size your tires are?
In the above example, each section breaks down as follows:
205 – Width of the tire in millimetres
55 – Aspect ratio – This is a percentage of the width (55% of 205mm). It determines how high or low profile the tire is
R16 – Rim diameter – The wheel rim size which this tire can fit on to, expressed in inches
91 – Load index – This number relates to how much weight a tire can carry when inflated to its maximum pressure.
W – Speed rating – Letters indicate how fast a tire can carry a load corresponding to its load index, under certain conditions. W = Max speed 168 mph (270 km/h).
What do the numbers on a tire mean?
Tire Size
Tire sizing can be confusing. Here’s how to read a tire size:
The first three-digit number in your tire size refers to the width of your tire, from side to side, in millimeters. For instance, in a size P215/65 R15 tire, the width is 215 millimeters.
The two-digit number after the slash mark in a tire size is the aspect ratio. For instance, in a size P215/65 R15 tire, the 65 means that the height is equal to 65% of the tire’s width.
The letter after the aspect ratio represents the type of vehicle (for example “P” stands for a passenger vehicle) and wheel diameter (for instance “16” stands for 16 inches). For instance, in a size P215/65 R15 tire, R indicates radial-ply construction and 15 is the wheel diameter.
Can you measure tire size with a tape measure?
Yes you can, but tape measure will not give you accurate results. Luckily, your tire size is easy to figure out.
Find Out How Tall Your Tires Are?
The easiest way to find out what size your tires are is by looking at the numbers and letters on the sidewall of your tires.
These markings are known as “tire codes” and they indicate everything from the type of tire to its dimensions and load capacity. The most important information you need is the tire’s width and height.
The width will be a three-digit number (such as 205), followed by a slash mark (/), then another number that represents the height (such as 60).
The height is also known as the profile or aspect ratio. In this example, the tire has a width of 205 millimeters and a height of 60 percent of its width, which means that the height is 123 millimeters (60% of 205 mm = 123 mm).
How do you read European tire sizes?
There are two systems in use for denoting tire sizes: The European Metric System and the P-Metric system. In the European Metric System, the first number is the width of the tire in millimeters, measured from sidewall to sidewall. The second number is the aspect ratio (height to width) of the tire’s cross-section to its width.
A 65 indicates that the height is equal to 65% of the tire’s width. The third number is the rim diameter code in inches.
The P-Metric system differs from the European metric system in that a letter precedes each number: P for Passenger car tires, LT for Light truck tires, T for Temporary or “space saver” spare tires, and ST for Special Trailer Service tires.
For example 185/65R14 86T means:
Tire Type – This is a temporary spare tire
Width – The tire width is 185mm
Aspect Ratio – The sidewall height, as a percentage of the width, is 65% of 185mm or 120.25mm tall
Construction – Radial
Wheel Diameter – 14″
Load Index – 86 = 1356lbs per tire (637kg) Maximum Load Rating at maximum air.
What do the 3 numbers mean on tire size?
Tire Width
The first three-digit number in the tire size refers to the tire width. For instance, in a size P215/65 R15 tire, the width is 215 millimeters.
Aspect Ratio
The ratio of height to width. The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size P215/65 R15 tire, the 65 means that the height is equal to 65% of the tire’s width.
What is the best way to measure for tire and wheel size?
If you want to know what size wheels and tires your car has, it’s important to check the tire sidewall numbers. These numbers will tell you the size of the wheel, as well as important information about how far the tire can be inflated and its maximum speed.
- Lay the tire down on its side to measure wheel diameter manually. If you cannot find a wheel diameter number on your tire’s sidewall, measure it yourself. Take the wheel out of your car, then lay it on a flat, smooth surface. Measure from one edge of the wheel to the other in inches; this is the diameter of your wheel.
- Measure width by placing a measuring tape across the top of the tread.
- Find out a tire’s aspect ratio by looking at its sidewall number (it will have an “R” before it). The aspect ratio is expressed as a percent or as a ratio; for example, if you see “R70,” this means 70 percent or 0.70:1. This means that for every inch wide your tire is, it is 70 percent as tall as it is wide; if your tire was 10 inches wide, it would be 7 inches tall (10 x .7 = 7).
How do you measure a rim for a rim protector?
Measure the diameter of the rim. Do this by measuring the distance between the widest point of the rim. Measure from the bed where the tire will sit. Do not measure from the outermost portion of the rim.
Measure the width of the rim. Measure this by measuring from inside to inside of each bead seat on opposite sides of the wheel. The width will be narrower than you think if you do not measure all around.
Measure the width of the rim. Do this by measuring from one outside edge to the other.
Measure for a full lip. This is a flat portion that extends about an inch past the surface of where you measured for diameter and width.
What are the different sizes of tire?
If you’re shopping for tires, there are a few things to look out for. One is the width — the measurement of the tire’s outside diameter.
Most tires are available in an inch size (measured in inches), but there are also other types of measurements: 55, 60, 65, 70, 75, 80, 85, and 90; this last one refers to the width of the tire at its largest point.
Widths come in different numbers. The more number of digits in a tire’s numerical designation (for example, “16X7”), the larger it is.
The narrower a tire gets from outside to inside (that is, from 8 to 10), the smaller it is. Unlike most other sizes and weights of vehicles and equipment, tires do not automatically increase in size with their rim diameter (width).
As a result, cars with bigger rims can only fit smaller-sized tires because they would be too wide for the larger rims on those cars; same thing with SUVs.
You can typically find cars or SUVs with inch rim sizes ranging from 12 to 16. However, you’ll likely need at least two inches of clearance between the edge of your car’s wheel well and the tire sidewall when parking your vehicle.
Frequently asked questions
1. How do you Find your tire size in inches?
The diameter of a tire is measured in inches and is always given as the width of the tire, followed by the letter “R” for “radial.”
The size that’s closest to 32.8 inches is listed first, then the second closest size listed, and so on. For example, if you need to know the diameter of a tire that’s listed as a 295/75R16, you’d multiply the width.
2. What does the size of a tire tread mean?
Tread depth is the measurement of how much tread there is on the tire. Tire tread depth is measured in one thirty-second of an inch (1/32″) increments.
Let’s say that you have a tire with a tread depth of 12/32″. That means there are 12 grooves in a circle, which is 1.5 inches deep.
If the tires you’re buying don’t have any worn grooves, the reading should be “12/32” as well. If they do have some tread worn off, you’ll need to know what that number is.
3. What size tires will fit stock rims?
If your rims and tires are stock, you have a few options for tire size. The most popular are 33-34 inches in size. For this size, you will be able to fit the largest tires on the market without rubbing (see above) if your rims are wide enough.
If you have narrow rims, you can consider 32” or even 30” tires for your F150. You still won’t be able to fit the largest tires without rubbing.
4. How do you find the right tire size For your vehicle?
It is important to know the tire size of your car before you begin shopping for a new set of wheels. Tire pressure may not seem like an important part of a vehicle’s performance, but it can be crucial in determining how well your car will handle on the road.
Air pressure inside each tire affects how much traction and control your vehicle has, which can make a significant difference in how fast you can get from point A to point B.
Conclusion
The tire size on your car is most often displayed in inches. The width of the tire in inches is measured on the outer edge of the tire and can be found printed near the sidewall. There are a couple of different ways to measure this width, but they’re all pretty much the same.
ABSOLUTE SIZING: The best way to measure tire width is from one sidewall to the other, across the full width of the tire. This measurement is called “absolute sizing” and gives you an accurate measurement.
Of course, this method works best for tires that are manufactured for your vehicle. If you want to find out if your current tires are made for your vehicle, you can check manufacturer specifications online or at your local dealer.
