A change inย wheel offsetย can give your car or truck a more aggressive look with a wider stance or help fit custom wheels that have a different offset compared to the factory wheels.
No matter the reason, you need to make sure the offset is within a range that wonโt rub your fender or suspension components.
How Is Wheel Offset Measured?
Wheel offset is measured as the distance between a wheelโs mounting surface and its centerline, usually in millimeters. It can be measured using a straight edge and ruler or by locating the offset information on the wheel itself.
In this article, weโll explore step-by-step everything you need to know about measuring wheel offset, its effects on handling and performance, and why itโs important for both safety and style.
Letโs take a closer look.

Table of Contents
How To Measure Wheel Offset
Here are the details and steps for measuring wheel offset:
Identifying The Mounting Surface
First up, you need to find the mounting surface of your wheel. Whatโs that, you ask? Well, itโs the flat part of the wheel that connects to the car or truckโs axle. Itโs usually hiding behind the center cap or hub of the wheel, so you might need to remove those first.
Measuring The Distance From The Centerline
Now that youโve found the mounting surface, itโs time to do some measuring. Youโll want to measure the distance from the mounting surface to the centerline of the wheel. The centerline is an imaginary line that divides the wheel into two equal halves. Hereโs a step-by-step guide to help you out:
- Lay your wheel flat on the ground or on a table with the mounting surface facing up.
- Take your measuring tape or ruler and measure the total width of the wheel. Be sure to include the entire width, from one edge to the other.
- Divide the total width by 2 to find the centerline. For example, if your wheel is 8 inches wide, the centerline would be at 4 inches.
- Next, measure the distance from the mounting surface to the centerline. This is your wheel offset.
Now youโve got your wheel offset! Keep in mind that the measurement might be in millimeters, so if youโre used to inches, you might want to convert it.
Wheel Offset Calculator
How To Measure Rim Offset With Tire On
So, you want to measure the rim offset without taking the tire off? No problem! Weโve got you covered. Just follow this simple guide, and youโll get your rim offset measurement in no time.
Tools Needed
Before we get started, letโs make sure you have the necessary tools handy. Youโll need:
- A straight edge or level (like a yardstick or a piece of wood)
- A ruler or measuring tape
Step-By-Step Guide
Hereโs how you can measure the rim offset with the tire still on:
- Park your car or truck on a level surface to ensure accurate measurements.
- Grab your straight edge and place it flat against the outside of the tire. Make sure itโs long enough to extend beyond the top of the wheel.
- With your ruler or measuring tape, measure the distance from the straight edge to the mounting surface (the flat part that connects to the axle). To find the mounting surface, look for where the wheel meets the brake rotor or drum. This is your โtire protrusion.โ
- Now, letโs find the wheelโs centerline. Measure the total width of the wheel, including the tire. Divide that number by 2 to find the centerline. For example, if your wheel and tire together are 10 inches wide, the centerline would be at 5 inches.
- Subtract the tire protrusion (step 3) from the centerline (step 4) to get your rim offset. For example, if the centerline is 5 inches and the tire protrusion is 2 inches, your rim offset would be 3 inches (5 โ 2 = 3).
What Is Wheel Offset Measured In?
Letโs dive into the world of wheel offset units and learn a bit about positive, negative, and zero offset, too. Understanding these units will help you make sense of your measurements:
Units Of Measurement (Millimeters)
Wheel offset is usually measured in millimeters (mm). This is because millimeters are a smaller unit than inches and can provide more precise measurements. In the tire and wheel industry, itโs common to see measurements like 35mm, 45mm, or even -10mm. So, when youโre dealing with wheel offsets, think millimeters!
Explanation Of Positive, Negative, And Zero Offset
Now that we know wheel offset is measured in millimeters letโs talk about the types of offset you might come across. There are three main types: positive, negative, and zero offset.
- Positive Offset:ย This is when the mounting surface is closer to the outside (road-facing side) of the wheel. In other words, the mounting surface is more toward the front of the wheel. Positive offset wheels are common in most modern cars, as they provide better handling and fuel efficiency.
- Negative Offset:ย In this case, the mounting surface is closer to the inside (car-facing side) of the wheel. Basically, the mounting surface is more toward the back of the wheel. Negative offset wheels are often seen in off-road vehicles or trucks because they provide a wider stance and more stability on rough terrain.
- Zero Offset:ย This oneโs easy! Itโs when the mounting surface is right at the centerline of the wheel. Neither inside nor outside, itโs right in the middle.
How To Measure Wheel Offset In Inches
If you already have a wheel offset measurement in millimeters and want to convert it to inches, itโs super easy! Just divide the millimeter measurement by 25.4. For example, if your wheel offset is 40mm, youโd do the math like this: 40 รท 25.4 = 1.57 inches. Voila! Now you have your wheel offset in inches.
What Is My Factory Wheel Offset?
There are a few places where you can find your vehicleโs factory wheel offset. Hereโs a list of options to get you started:
- Vehicle ownerโs manual:ย One of the easiest places to find the factory wheel offset is in your vehicle ownerโs manual. Check the โWheels and Tiresโ section for this information.
- Online forums and websites:ย Many car enthusiasts and experts discuss wheel specs in online forums or websites. Search for your vehicleโs make, model, and year, followed by the term โfactory wheel offset.โ
- Dealership or manufacturer:ย If all else fails, you can always contact your car or truckโs dealership or manufacturer. They should have the factory wheel offset info on hand.

Where Is The Offset On A Wheel?
Letโs explore how to locate the offset on a wheel and make sense of the markings:
Finding The Wheel Markings
Wheel manufacturers often stamp or etch important information, like the offset, onto the wheel itself. Hereโs where you can usually find these markings:
- Backside of the wheel:ย Most of the time, youโll find the wheel offset marking on the backside of the wheel, near the center hub area. You may need to remove the wheel from your car or truck to see the marking clearly.
- Spoke area:ย Sometimes, wheel manufacturers place the offset info on one of the spokes of the wheel. Look for any stamped or etched markings on the spokes.
- Wheel rim:ย Occasionally, the offset information can be found along the inside rim of the wheel. This location is less common but worth checking if you canโt find it elsewhere.
Understanding The Markings
Once youโve found the wheel offset marking, you might see a number followed by the letters โETโ or โOFFSET.โ The number represents the wheel offset in millimeters. For example, if you see โET45โ or โOFFSET 45,โ it means the wheel has a positive offset of 45 millimeters. Keep in mind that if the number has a โ-โ symbol before it, like โ-12,โ it indicates a negative offset.
Decoding Other Wheel Markings
In addition to the offset, you might also see other markings on your wheel. These can include:
- Wheel diameter:ย The size of the wheel measured in inches (e.g., 17, 18, or 19).
- Wheel width:ย The width of the wheel measured in inches (e.g., 7, 8, or 9).
- Bolt pattern:ย The arrangement and number of lug holes (e.g., 5ร114.3, which means five lug holes with a 114.3mm diameter circle).
How Does Wheel Offset Affect Handling And Performance?
Letโs go through the key points to better understand the relationship between wheel offset and your car or truckโs performance:
Positive Vs Negative Offset
Remember that a wheelโs offset is the distance between its mounting surface and its centerline. Positive offset means the mounting surface is closer to the outside of the wheel, while negative offset means itโs closer to the inside. Hereโs how these different offsets can affect your ride:
- Positive offset:ย Wheels with a positive offset generally improve handling and stability because they maintain your vehicleโs suspension and steering geometry. However, if the offset is too positive, it can cause rubbing against the fender or suspension components.
- Negative offset:ย Wheels with a negative offset can provide a more aggressive appearance and a wider stance, but they can negatively affect handling and lead to increased tire wear. Additionally, the extra stress on the suspension components may lead to premature failure.
Impact On Handling
Wheel offset can directly impact your vehicleโs handling characteristics. Here are some of the ways it can affect how your car or truck drives:
- Steering response:ย A wheel offset thatโs too far from the factory specs can cause your steering to feel heavier or more sluggish, making it harder to maneuver your vehicle.
- Cornering:ย A proper wheel offset helps maintain the ideal balance between tire grip and body roll during cornering, while an improper offset can lead to unpredictable handling and a higher chance of losing control.
- Stability:ย The right wheel offset contributes to overall vehicle stability, while an incorrect offset can lead to poor handling at high speeds and reduced braking efficiency.
Impact On Performance
Wheel offset also has an influence on your vehicleโs overall performance. Hereโs how:
- Tire wear:ย Improper wheel offset can cause uneven tire wear, reducing the lifespan of your tires and potentially affecting your vehicleโs safety.
- Fuel efficiency:ย A wheel offset thatโs too far from the factory specs can negatively impact your vehicleโs fuel efficiency, as it causes extra stress on the suspension and steering components.
- Acceleration and braking:ย An improper wheel offset can reduce acceleration and braking efficiency due to the changes in suspension geometry and increased stress on the vehicleโs components.
Resources
Below are some links you may find helpful when learning about tires
Final Thoughts
To wrap it all up, knowing about wheel offset is super important for anyone who owns or loves cars and trucks. Weโve looked at everything there is to know about wheel offset, from how to measure it to how it affects the way our vehicles drive. Itโs good to remember that having the right wheel offset doesnโt just make our cars and trucks look cool, it also helps keep them safe and stable while weโre driving.
With this knowledge in your back pocket, you can make smart choices when you want to change or upgrade your wheels. Youโll be able to keep your car or truck running smoothly, looking awesome, and staying safe on the road.
Good luck and happy motoring.