Your Ultimate Tire Calculator for Perfect Wheel Fitment

Tire and Wheel Sizing guide

Understanding Offset and Backspacing

When it comes to wheels, two important measurements to consider are offset and backspacing. The offset refers to the distance from the hub mounting surface to the centerline of the wheel, typically measured in millimeters. On the other hand, backspacing is the distance from the hub mounting surface to the inside lip of the wheel, usually measured in inches.

Choosing the right wheels requires careful attention to backspacing. Offset can be categorized into three types: positive, negative, or zero. For instance, a wheel with a +12mm offset is considered positive, while a wheel with a -12mm offset is negative. The centerline of the wheel is denoted by "0". A +12mm offset means the hub mounting surface is positioned 12mm (slightly over half an inch) further towards the front of the wheel, which is common in front-wheel drive cars. Conversely, a -12mm offset indicates that the hub mounting surface is located 12mm inside the wheel's centerline, closer to the back side of the wheel lip. Wheels with negative offset often have a "deep" appearance compared to those with zero or positive offset.

Most factory truck wheels have some degree of positive offset.

If you install a wheel with less backspacing than the factory wheel, the new wheel will stick out further than the original.

Zero Offset: The hub mounting surface aligns with the centerline of the wheel.

Positive Offset: The hub mounting surface is towards the front or wheel side of the wheel. Positive offset wheels are typically found on front-wheel drive cars and newer rear-wheel drive cars.

Negative Offset: The hub mounting surface is towards the back or brake side of the wheel's centerline. "Deep dish" wheels often have a negative offset.

Choosing the correct offset is crucial for proper vehicle handling. When you change the width of the wheel, the offset value also changes. If the offset remains the same while you increase the width, the extra width will be divided equally on the inside and outside. However, this arrangement may not work well for most cars. At our company, we have extensively tested the fitment of thousands of different vehicles. Our knowledgeable sales staff relies on our comprehensive database to provide you with the perfect fit for your vehicle.

In addition to offset, backspacing is another important factor to consider. Similar to offset, backspacing measures the distance from the hub mounting surface to the inside lip of the wheel, expressed in inches.