How to Use a Wheel Offset Chart

So, you’ve found yourself in the market for a new pair of rims. And not just any rims—you need something unique, different, and wicked. 

You find yourself browsing Rent A Wheel and seeing a ton of different options. Some look flush and tucked in with the body of the car, and others seem to have deep wells that stick out a bit. 

These looks are known as a positive or negative offset, and they do look very cool when they’ve been properly fitted. 

However, it could be bad news for your suspension and brake systems if you get the wrong wheels on there. That’s why it’s majorly important to make sure you’re getting the right rims. 

We make buying rims extremely easy at Rent A Wheel. Our professional tire technicians are available to chat online anytime to find the perfect match for you and your ride. Plus, our cutting edge visualizer will present rims that will fit your car and show you how they’ll look cruising down the street. 

If you’re interested in measuring rims for yourself, we don’t blame you. It’s important for a driver to be well versed in every aspect of their vehicle, and we applaud you for doing your research. 

A Wheel Offset Chart will help make getting accurate measurements easy. First, let’s take a step back and cover the basics. Here’s a crash course on offsets. 

What Is Wheel Offset?

Simply put, wheel offset is the measurement from the direct centerline of the rim to the connection surface.

The centerline is the line that cuts down the center of the wheel, which makes sense. If you picture your rim standing up straight, the line would cut through your rim the long way to create two equally wide discs. 

Offset is the value in millimeters from the centerline to the connection surface, which is where the wheel connects to the car. The different types of offset are distinguished by which side of the wheel is closer to the connection surface. 

Different Types Of Offset

There are three different types of offset: 

• Negative offset

• Positive offset

• Zero offset

Positive Offset

The face of the wheel is the side closest to the curb when you park. When a wheel has a positive offset, the connection surface is closer to the face of the wheel. The wheel will tuck into the body of the car, and the rim will be closer to the front of the car.

When a rim has an extremely positive offset, the connection surface is essentially on the rim’s face. The rest of the tire is within the frame of the car. 

This looks very clean. Some people love this type of wheel, like the Lexani Wraith. Performance or foreign car drivers are more likely to recognize this look. However, going too far with a positive offset can have negative side effects. (See what we did there?)

If your wheel is too far inside of your wheel well, you run the risk of bumping into your suspension system if you turn too hard. If your brake system is too close to the wheel at high speeds, your rim may expand due to the heat and damage your brakes. 

Like we said: it’s important to properly measure your rims. 

Negative Offset

Negative offset is the opposite of positive offset (duh). This means the connection surface is closer to the wheel’s back side, away from the curb. 

A wheel has a negative offset if it looks like you could pop it off and use it to bake a deep dish pizza. The hub cap is sunken deep into the rim itself, providing killer inner wheel wells that look awesome cruising around the city or off-roading somewhere extreme. If you’re still having a hard time picturing it, take a look at the absolutely amazing Mayhem Combat. 

However, just like positive offset wheels, these wheels can have issues. 

Too much negative offset risks putting too much abnormal weight on your suspension system. Imagine that you’re holding a weight in each hand. The further you extend the weights away from your body, the more difficult it is to keep them up.

Your car feels the same way, and it just wants to be treated and cared for properly. Make sure you’re not too excessive when adding a negative offset. 

Zero Offset

Zero offset occurs when the connection surface is perfectly in line with the centerline of the wheel: not too far back, not too far forward, just right. 

Most commercial vehicles don’t come with perfectly zero offset, but they get pretty close to it. 

The Backspace

It would be doing you dirty to talk about wheel offset measurements and not bring up the backspace. 

The backspace is the measurement from the edge of the rim lip to the connection surface. This is much easier to find than offset, and it provides an easier way to accurately measure offset.  

To measure the backspace, place your rim face down on the floor, preferably on a carpet or towel so you don’t scratch that pretty face. 

Next, take a flat, straight bar or something similar and place it across the open back of the wheel. Try to place it so that one edge of your bar is as close as possible to the center of the wheel, just along the diameter. 

Then, take a measuring tape or ruler, and measure down into the wheel well’s connection surface. Remember, you’re looking for an accurate measurement of the distance from the connection surface to the back edge of the rim. 

How To Measure Offset

Now that you have your backspace, the offset just requires some quick math. 

Let’s say your rim is ten inches wide, and you know your backspace measurement is seven inches. You know that your centerline is half of the wheel width. That’s five inches. If your backspace is seven, you’ve have two inches more backspace than centerline, meaning you have two inches of positive offset. 

That’s… a bit of mental math. To make things even better, you have to convert that two inch result into millimeters. It’s not the end of the world, but why not save yourself the trouble?

Here comes the Offset Chart. 

How The Wheel Offset Chart Comes Into Play

The offset chart is a tool you can use to skip the math and measurement conversions once you know your width and backspace. It saves you time and mental anguish. When you’re shopping for new rims and looking at a ton of options, it’ll definitely come in handy.

To start, here is the chart itself:

It might look a little confusing, but once we break it down, it makes total sense. 

Measuring your wheel width and backspace is fairly easy, and most of the time wheels shift between these measurements in half inch increments. 

If you have your ruler and straight bar, you can measure your wheel width. Say, for example, that it’s ten inches. Lay the wheel on its face and measure the backspace. Here, it’s four inches.

Now, you can use the chart to find the offset number (in millimeters, of course) for those two measurements. In this case, it would be -25.4 millimeters of offset. That’s Negative offset, if that wasn’t clear. 

Summary

We’re strong believers that drivers should learn everything they can about their cars, whether they’re discovering an existing part or exploring a new change. 

Make sure you know everything you can about custom offsets before you make any big changes. 

With this information and this chart, it’s quick and simple to determine a wheel’s offset and know exactly what you’re seeing. Rent A Wheel makes this process even easier.

Our tire techs are on standby to chat with you about the perfect wheels to match your sick ride. With our state-of-the-art visualizer, we show you rim options that will fit your car and how they’ll look when installed.

Speaking of installations, have we mentioned that when you shop with us we’ll do a free installation and balance at your local Rent A Wheel shop? With our flexible payment plan options, there’s never been a better time to pick up a sick new set of rims with whatever offset you want. 

References:

Understanding Wheel Offset: Negative vs Positive Offset Explained | Low-Offset

What is wheel offset and why is it important? | Bimmer Tips

How to Measure Wheel Offset | EFX Tires