When it comes to putting wheels on our cars, proper fitment, spacing, and size seems to be an issue with a lot of cars. Wheels that have the wrong backspacing can cause the tire to rub, as can a wheel/tire combination that is too big. Jegs Performance has put together a video to help show us how to properly measure a wheel, and how to measure for proper backspacing and width prior to ordering wheels.

If you’ve wanted to know whether your friend’s wheels will fit your car, or if that used set of alloy wheels you found online will fit your car, these simple tips can help you make that determination. How many of us have bought used wheels and the seller told us that the wheel was eight inches wide, only to find out that they measured incorrectly? It happens all too often.

In the video above, Jegs Performance shows the proper way to measure the width and the diameter of a wheel, and although it might seem obvious to some, it’s a good instructional video for those who are not sure. For starters, wheels should be measured at the point where the tire beads to the wheel, and not the outer edges of the wheel.

For instance, a wheel that has a corrected size of eight inches wide could be almost nine inches wide if measured (incorrectly) from outside edge to outside edge. While that additional inch might not seem like much, tires are designed to fit on a wheel that fits in a certain width range, and that is typically a suggested range provided by the tire manufacturer.

When it comes to measuring the bolt pattern, we’re shown the proper way to measure for a four, five, six, or eight lug wheel. For the even-numbered bolt pattern, measurement is taken across the center of the wheel to the center of the two opposing lugs. But for the five lug wheel, the measurement is taken from the center of one lug to the back side of the second lug away from it.

Another area that has a lot of people confused is wheel backspacing versus wheel offset. The wheel offset is the distance between the inside face of the wheel (where it mounts to the hub) to the wheel center line. A positive offset means that the distance is greater than zero, meaning the car side of the wheel is deeper than the road side of the wheel. This is typical for FWD cars and many modern cars.

Jegs offers tools to help measure for wheels.

A negative offset means that the distance is less than zero, meaning the road side of the wheel is deeper than the car side of the wheel. This is typical of older, RWD cars and is often considered a deep dish type wheel.

Backspacing is the distance between the inside face of the wheel and the lip on the back side of the wheel, where the tire seats. Backspacing is always a positive number, and has nothing to do with offset as it is a hard measurement that doesn’t rely on the wheel center line.

You can also buy Percy’s WheelRite Wheel Fitment Tool (PN 760-01201) from the Jegs website to help determine the proper wheel diameter, width, and offset. It’s a great investment in tools when it’s time to invest in wheels, and helps to ensure you get the right fitment the first time.