How to Read, Measure, and Choose ATV Tire Size

Last Updated on November 26, 2023 by ATVNotes

ATVNotes is reader supported, If you buy anything through links on our site, we may earn an affiliate commission. Learn More.

The right ATV tire size is crucial for your ride performance and safety. The tire size affects various factors, including traction, ground clearance, and stability. A smaller tire size provides better acceleration, while a larger tire offers more top speed and better stability on rough terrains. So, it’s important to read, measure, and choose the precise tire size, written like a code, that matches your riding style and terrain type. 

Understanding the numbers and letters that make up the code is essential to end up with your target tire. The first indicates the tire’s height, while the second represents the width. The letter/dash following those two numbers indicates the tire construction or load rating – “R” stands for radial tires, and “B”/”-“(dash) stands for bias ply tires.

In this guide, you will have all the numbers indicating tire diameter/height, width, and rim diameter broken down so that you can precisely determine the ATV tire size corresponding to your riding purpose, terrain, and style. This is crucial to prevent any accidents or issues caused by incorrectly sized tires on your vehicle. 

How Does ATV tire size affect riding performance?

ATV tire size directly influences the machine’s performance and, thus, the quality of your off-road adventures in your chosen ATV zone. Tire size affects the overall weight and handling of an ATV, which can impact several aspects of performance, including acceleration, braking, speed, and maneuverability. Larger tires tend to be heavier than smaller ones, affecting how quickly the ATV accelerates and brakes.

The size of the tire also plays a role in the top speed that an ATV can achieve. The larger the tire, the higher its circumference will be. This means a bigger tire will cover more distance with each rotation than a smaller one. As a result, ATVs with larger tires may have higher top speeds than those with smaller ones.

Finally, tire size can affect how well an ATV handles different terrains. Bigger tires provide better traction and stability on rough terrains like mud or rocks. However, they may not be as nimble on flat surfaces because their weight makes them harder to steer and turn quickly. Smaller tires are lighter and easier to handle but may not perform as well on rocky or muddy terrain due to less surface area making contact with the ground for grip. 

So, the performance of your ATV translating to your riding comfort and quality depends largely on selecting the right tire size matching your riding level, style, and intended terrain. For that, you must be able to read the code written on the tire sidewall. 

How Do You Read ATV Tire Sizes?

ATV tire sizes can be confusing, especially for those new to ATV riding. Understanding how to read ATV tire sizes is essential for choosing the best options based on terrain conditions and your vehicle specifications. However, understanding the numbers and letters on your tires will suffice to read ATV tire sizes correctly. 

The first number indicates the tire’s height in inches, while the second number represents its width in inches. The third number denotes the diameter of the wheel rim in inches where you intend to mount your tire. For example, if your ATV tire reads 25×8-12, it means that it has a height of 25 inches and a width of 8 inches and fits on a 12-inch wheel rim.

Additionally, some ATV tires may have letters in place of the dash (-) following the first and second-size specifications. Suppose the above size can be written 25*8R12 on your tire size wall. That letter indicates other important features, such as their load capacity rating or speed rating. A “B” or “–” (dash) before the rim diameter measurement suggests it is a bias-ply construction, while an “R” indicates a radial construction. 

How Are ATV Tire Sizes Coded/Written?

Knowing the numbers and letters should help you decipher he ATV tire sizes. But nowadays, some manufacturers tend to write ATV tire sizes in metric tire sizing charts once only used for car tire sizes. That scenario necessitates understanding the types of ATV tire sizing – imperial standard tire sizing & metric tire sizing. 

ATV Tire Size

Imperial/Standard ATV Tire Sizing Chart

The sizing already described in the previous section is imperial or standard tire sizing. The first number in imperial ATV tire size indicates its height or diameter in inches. The second number refers to the tire’s width from sidewall to sidewall. The final number indicates the rim diameter that the tire will fit on.

For example, a common ATV tire size is 25×10-12, indicating a height of 25 inches and width of 10 inches, and will fit on a 12-inch rim. You already know what that sign (-) stands for.

Metric ATV Tire Sizing

A metric ATV tire sizing chart provides information on the tire’s width, aspect ratio, and rim size. The first number in the metric sizing chart represents the width of the tire in millimeters. The second number refers to the aspect ratio or height of the sidewall as a percentage (80%) of its width. The letter before the third number or diameter of the rim in inches stands for tire construction type – R for Radial and B for Bias.

While standard sizing charts typically list each tire’s width, height, and rim diameter in inches, metric sizing is a mix of both. On a metric chart, you will come across code 205/80R12 presenting a tire width of 205 millimeters, an aspect ratio percentage of 80%, R for radial construction type, and 12 inches as the rim diameter. 

Metric ATV Tire Sizing

How to Convert a Metric ATV Tire Size into Standard One? 

For some, especially the novice off-roader, metric ATV tire sizes can be confusing and may require you to convert the size code into standard tire sizes. We already know the numbers on the sidewall of a metric tire indicate the width in millimeters, the aspect ratio in percentage, and the rim diameter in inches.

To convert those for standard tire size, the first two numbers into tire height and width in inches. You will need to use a conversion chart or online calculator.

  • First, take note of the three numbers on the sidewall of your metric ATV tire. The first number refers to the width in millimeters, while the second number indicates the aspect ratio as a percentage of the width. Finally, the third number represents the rim diameter in inches not needed to convert.
  • To convert these measurements for a standard ATV tire size, divide the first number by 25.4 to find the width in inches. Then, do the math to find the tire height from the aspect ratio. And the third number needs no conversion as this measurement is given in inches in both the tire sizing format. 

It is important to note that not all metric-sized tires have exact equivalents in standard sizing. In such cases, consulting with a professional mechanic or shop assistant for guidance is recommended before making any purchase decision. 

Understanding ATV Tire Size Measurements In-depth

When shopping for new ATV tires, double-check with your manufacturer or mechanic about what specific sizes you need for your particular vehicle model and intended usage before purchasing anything. Knowing what specific height, width, and rim size you need for your level and purpose of ATVing will get you the perfect option.  

Tire Diameter

Tire diameter is a crucial factor in the performance of an ATV. It determines how the tire interacts with the terrain and affects the overall ride quality. The diameter is measured from one end of the tire to another, passing through its center. In general, larger tires offer better ground clearance and improved traction on rough terrain.

ATV tires are typically categorized by diameter, ranging from 12 inches to 32 inches or more. 

  • Sports quads use smaller tires that are suitable for light-duty applications: 20-25 inches 
  • Utility quads use medium size tires for farming or yard work: 24-28 inches
  • Larger ones are best for off-road adventures on rock crawling, muddy trails: 27-32 inches

Tire Width

The width of your tires affects everything from your vehicle’s handling and stability to its overall performance on various terrain types.

Tire width is typically measured in millimeters/inches and can range from narrow widths of around 7-8 inches for smaller wheels and up to 10-14 inches for larger ones. Wider tires offer more surface area and traction, ideal for off-roading and other challenging environments. However, they may also be more difficult to maneuver in tight spaces or high speeds. Two smart ways to determine your ATV tire width include:

  • Following what your wheel manufacturer instructs in the manual
  • In fact, this instruction is not available; do not worry. As a general guideline, you can go for a wheel 2 inches narrower than your tire width. 

However, the best tire width for your ATV will depend on various factors, such as your driving style, typical terrain type, and other personal preferences.

Wheel/Rim Diameter

A precise ATV tire size requires you to find the exact diameter of the wheel. The wheel diameter is crucial in determining how your ATV performs on different terrains and conditions. Typically, wheels come in sizes ranging from 8 inches to 14 inches, with some models even exceeding this range.

Smaller-sized wheels are often found on entry-level ATVs and are designed for easy maneuverability and agile handling in tight spaces. These wheels offer excellent acceleration capabilities but have less top-end speed than larger wheels.

On the other hand, larger-sized wheels provide better traction, stability, and ground clearance allowing riders to tackle more challenging terrains with ease.

Choosing the right combination of wheel diameter and tires depends on what type of riding you plan on doing with your ATV. 

How to measure ATV tire size?

Measuring the size of your ATV tire is a simple process that can be done with just a few tools and several steps. You can take your ATV tire size measurements in a few steps using a tape measure, ruler, and caliper. Here you go.

How to Measure ATV Tire Sizes

Identifying Tire Size

The first step is identifying the tire size, usually found on the tire’s sidewall. The size will typically be listed as three numbers, such as 25×8-12, which indicates the width, height, and rim diameter. 

Measuring Tire Width

To measure the width of your ATV tire, you’ll need to use the tape measure. Place one end of the tape at one edge of the tire’s tread and stretch it across to the other side. Make sure to take this measurement in millimeters or inches, depending on what unit is provided in your ATV manual.

Measuring Tire Height

To measure your ATV tires’ height or overall diameter, place a straight edge across from one side wall to another at the widest point on its circumference. Then using a ruler or measuring tape, determine in inches or millimeters from where you have placed the straight edge to ground level. 

Measuring the rim diameter

To begin with, remove the wheel from the ATV and place it on a flat surface.

Next, measure the distance from one end of the rim to another using any of the tools mentioned above. Make sure to take multiple measurements at different points around the rim’s circumference to ensure accuracy. Once you have all your measurements, average them for your final measurement.

It’s important to note that some rims may have protruding edges or lips that can affect your reading. In such cases, consider these protrusions when taking your measurement by adding their height or depth accordingly. 

Measuring these dimensions accurately will help ensure you select proper replacement tires for your ATV that offer better performance when riding on trails or any tough terrains out there or doing utility chores. 

How to determine ATV tire size?

To determine the appropriate ATV tire size, it is crucial to understand your vehicle’s specific needs. Several factors are getting directly affected by the size of ATV tires, including the type of terrain you will be driving on and the desired level of stability and control. But when determining your ATV tire size, one dominant factor comes into play: the type of terrain to ride. 

We have covered how and why different ATV trails and terrains require different sizes of tires in the tire width breakdown section. That says how the novice just starting should go by the following criteria. 

  • Small Size Tire (20-25 inches) will give a better experience in easier terrain riding for sports and racing.
  • Medium Size Tires (24-28 inches) will perform the best in dunes and wet trails for recreational and utility purposes.
  • Larger tires (27-32) offer the best control in deep mud, rock, and wood.

However, if you are replacing the old and worn-out one, the easiest and the most recommended ways to determine the right tire size include the following:

  • Consult your owner’s manual or contact a reputable dealer for advice. They can provide recommendations based on your make and model and any aftermarket modifications you may have made.
  • To read the tire size code inscribed on the sidewall of your old tire.  

Can I Put Bigger Tires on My ATV?

When it comes to ATV tire size, bigger is only sometimes better. While many riders may want to put larger tires on their ATVs for aesthetic or performance reasons, it’s important to consider the potential drawbacks. 

Firstly, larger tires can cause clearance issues and lead to damage from rubbing against other parts of the vehicle or terrain.

Additionally, bigger tires mean more weight and resistance, which can negatively impact acceleration and handling. 

It’s also important to note that changing the tire size on your ATV can affect its overall gearing ratio, which could result in decreased power and speed. However, if you have to upgrade the tire sizes to bigger sizes, you can go, at best, two inches up compared to your wheel size. 

Before making any changes to your ATV’s tire size, consult a professional mechanic or manufacturer guidelines to ensure you make a safe and appropriate modification. 

Right ATV Tire Size for optimal performance and safety 

Selecting the right tire size for your ATV is essential for its performance and safety. The correct tire size will ensure that your vehicle has optimal traction, stability, and maneuverability on any terrain. A larger tire may seem like a good idea to some riders as it increases ground clearance but can negatively affect handling and stability, especially when turning at high speeds.

On the other hand, smaller tires may not provide sufficient ground clearance or grip on rough terrains. It’s important to always refer to your ATV owner’s manual before purchasing new tires to determine the recommended tire size for your specific model. Additionally, consulting with an expert or experienced rider can help you decide which tire size will best fit your riding style and needs.

Choosing the right tire size amounts to end up with the right ATV tire. It is crucial to maintain optimal performance and safety while riding an ATV. So take time to research thoroughly before deciding to upgrade or replace your current tires.

Leave a Comment