Do you want to compare tire sizes before making a purchase? Do you know what a 245 and a 265 are? Maybe a 285 and a 315? Well, it depends on a few factors. Metric sizes are more challenging to decipher when determining a tire’s size. With the other two, such figures are merely exemplary. A 33 is a 33 regardless, but a 265/70/16 tire is 30 1/2″ tall, and a 265/75R17 tire is 32 1/2″ tall. To find all of your tire size comparison needs, you should utilize the tire size/height comparison calculator.
- What is tire height?
- What is the tire size?
- How is tire size/height calculated?
- Do wider tires ride better?
- Why should we use a tire size and height comparison Calculator?
- What factors should you think about before changing your tire height or size?
What is tire height?
It’s the sidewall height represented as a percentage of tire width, measured from the wheel rim to the top of the tread. In other terms, it’s tire width divided by sidewall height. If the aspect ratio is 65, the sidewall is 65 percent as tall as the tire is wide.
What is the tire size?
Finding the manufacturer-recommended tire size should be simple no matter what car you drive. The owner’s manual is the perfect place to start looking. If you can’t find the handbook, don’t worry; you might be able to obtain a tire fit guide in these places:
- The jamb on the driver’s side door
- Inside your glove compartment’s door
- Within the hatch of your gas tank
Tire size information can also be found on the sidewall of your current tires (provided they’re the right size). No matter where you look for your tire size, you’ll have to figure out a series of numbers and letters.
Let’s go over each number or letter in the order they occur in your tire size data and see what they mean. As an example, consider the following tire size: P225/70R16 91S.
The letters “P” and “LT.”
Before the number sequence begins on most vehicles, you’ll see the letter “P”: P225/70R16 91S. The “P” stands for “P-metric,” which is the Tire and Rim Association’s designation for a “passenger car” tire. A “P” indicates that the tire is primarily used on passenger vehicles, such as automobiles, minivans, SUVs, and other light-duty pickup trucks.
If you notice “LT” instead of “P,” it means you need “light truck” tires; “LT” stands for “LT-metric,” a Tire and Rim Association classification for a “light truck” tire. Light truck tires are made to be used on vehicles that can pull trailers or carry big loads.
“T” stands for “temporary” and refers to your spare tire. “ST” stands for “special trailer” in this case. A particular trailer tire is never installed on the drive or steering wheels. It means to be used on axles on trailers.
The width of the correct tires for your vehicle, in millimeters, is the first number in your tire size information: P225/70R16 91S. The distance between two sidewalls is always referred to as tire width. For example, a tire with the designation “P225” is designed for passenger vehicles and has a nominal width of 225 millimeters.
The tire’s aspect ratio is the number after the slash mark, which tells you how tall your tire profile is: P225/70R16 91S. Aspect ratios are presented as a percentage. The aspect ratio is measured by dividing the width of a tire by the height of its sidewalls. For example, the height of a tire with an aspect ratio of 70 is 70 percent of its width. If tires with a lower aspect ratio, such as the 60 series, typically outperform tires with a higher aspect ratio, such as the 75 series, in vehicle handling.
After the aspect ratio, the tire’s construction is indicated with P225/70R16 91S. The letter “R” shows the internal structure of your tire and provides an indication of its stability. On the sidewall of a tire, there are two different kinds of construction.
According to Hemmings, a historic vehicle website, r – Radial, D – Diagonal, or “Bias-ply” tires were used on cars and light trucks until the 1970s. On the other hand, Radial tires make up the great majority of tires on the road now in the United States. Radial tires have been the mainstream technology for almost 40 years, so you’ll always find the letter “R” on tires. Internal ply cords are aligned in a radial orientation in radial construction tires (at 90 degrees to the centerline of the tread).
The diameter of the wheel is the following number. A tire with the size P225/70R16 91S, for example, would fit a rim with a diameter of 16 inches. If you change the size of your rim, you’ll also need new tires compatible with the new size. Tires built for 16-inch wheels will not extend to fit on new 18-inch wheels.
How is tire size/height calculated?
Our calculator uses the following formulae to calculate the dimensions:
Section Height = Aspect Ratio × Tire Width
Tire Diameter = Wheel Diameter + 2 × Section Height
The tire code provides measurements for the aspect ratio and tire width. The tire width is the three-digit number in millimeters preceding the forward-slash (/) in the tire code. The aspect ratio is the two or three-digit value after the forward-slash. The section height is their product.
The tire diameter can be measured using the section height and the wheel diameter once the section height has been determined. Another measurement provided by the tire code is the wheel diameter. The tire’s internal construction is indicated by the 1- or 2-digit number following the letter. The internal structure is not always included, and the wheel diameter always follows the aspect ratio of the tire code. Inches are used to measure a wheel’s diameter. The tire diameter equals the sum of the wheel diameter and the section height multiplied by two.
Do wider tires ride better?
You have a choice, and each option has its own set of benefits and drawbacks. If you want a smoother ride, stay away from larger wheels. Larger wheels produce a harsher ride, whereas a smaller wheel and a thicker tire can provide a smoother ride without major vehicle adjustments.
While larger-diameter wheels and tires could improve handling and high-speed performance, lower-profile tires have a harsher ride and are potentially noisier than conventional rubber. The additional weight of the larger tires may outweigh some of the possible performance benefits. When making tight turns or when the suspension bottoms out, the tires may rub against the fender well if the replacement wheels and tires are more significant than the originals. As a general rule, fitting a tire up to 20 millimeters wider than stock on the original rim is safer.
Why should we use a tire size and height comparison Calculator?
Use our tire size calculator to determine the diameter, width, sidewall, circumference, and revolutions per mile of any tire. Simply enter a metric or standard tire size and press the calculate button.
Inch measurement tires are very simple to comprehend, but metric tires have a more challenging system to decipher. The width in millimeters is the first number on a metric tire. Because there are 25.4 mm in 1 inch, divide this value by 25.4 to get the inch equivalent. The wheel diameter is the third number, which is usually followed by an “R.” In metric tire sizes, the sidewall or aspect ratio is employed to determine the overall height of the tire. The sidewall measurement is calculated using the second digit on a metric tire. The tire’s sidewall height is calculated as a proportion of its width. The second number represents the percentage. A 285/75/R16 tire has a sidewall height of 75% of 285mm, or “aspect ratio.”
To convert the diameter of a metric tire to inches: (#1 x #2 / 2540 x 2) + (#3)
For example: 285/75R16 (285 X 75 / 2540 x 2) + 16 = 32.8 inches tall.
This is done for you by the tire calculator. Simply enter in any tire size and hit the calculate button. It also eliminates the problem of picking which tire to run if you have an inch tire measurement in mind but can’t find a firm that makes that size. Simply enter your inch measurements, and it will populate suggested tire choices that are one inch bigger or lower than the entered tire size. Because metric tires offer more options and options, a tire size calculator can be quite beneficial.
What factors should you think about before changing your tire height or size?
A person’s tire/wheel size may be changed for various reasons. It is frequently done for aesthetic reasons. When altering the size of a tire or wheel, multiple factors must be considered. Otherwise, there could be profound implications, such as increased wear and tear on the vehicle’s suspension and brake components (especially anti-lock brakes), which could compromise handling or cause other mechanical issues with the car’s transmission.
Increase the size of the rims.
Increasing the size of the rims is a popular adjustment. The change in tire size is one of the most important factors to consider while changing the size of a car’s rims. Because the tires must be tiny enough to fit inside the car’s wheel, wider rims are usually required with thinner tires. Tires with a diameter change of less than 3% from the factory-specified tires are generally recommended.
All of the tires should be replaced at the same time.
People replace their tires for various reasons, including aesthetics, blowouts, and wear and tear. You should replace all of the tires simultaneously when replacing them. If this is impossible, at the very least, the front two or back two tires should be replaced simultaneously, depending on whether the tire in question is at the front or back. If only one or a few tires need to be replaced, it is strongly advised that the tires be of the same type and brand. Tire differences can create a variety of concerns while driving, including loss of control or spinouts, inaccurate speedometer readings, and even damage to the vehicle’s stability system calibrations.
Changing tires also affects the speedometers and odometers.
Because speedometers and odometers are calibrated based on stock tires, changing tires impacts them. Therefore, while it is feasible to safely utilize different-sized rims and tires on a car, the automobile will nonetheless change. The total circumference of the wheel is increased by larger rims and tires, which increases the distance around the tire. Because both the speedometer and the odometer depend on how many revolutions the tire produces, resulting in erroneous readings. A larger tire, in particular, will result in a lower speedometer reading than the real speed of the automobile; similarly, it will result in a lower odometer reading than the actual distance traveled.
The proper tire installation is critical to your vehicle’s overall performance and safety. The conditions you travel in and your vehicle response and handling preferences should influence your tire selection. As a result, you’ll need to know how to read tire size when it’s time to buy tires in the future to make the best option.