Video: Weld Racing’s Bolt Circle and Back Spacing Measurement How-To

One of the most common questions that novice car guys have when it comes to hub and wheel selection is in regards to the bolt circle – or more specifically, how they go about measuring it. Well, the folks at Weld Racing, one of the most respected manufacturers in the automotive and racing industry, has provided a great resource for how-to information via their Weld Racing video channel with a range of video guides. And to help further educate would-be wheel buyers, they’ve provided a great new video on how to properly measure and determine the bolt circle of your particular vehicle.

Just as the video will explain, measuring a hub with an even-numbered bolt layout (ie 4,6, 8 lugs) is a relatively simple process, but the odd-numbered layout adds a little extra element to it.

To measure an even-number layout, take a ruler or other flat measuring device that won’t bend or flex like a tape measure and measure from bottom edge to bottom edge of two opposing bolts and with an accurate measurement, you should be able to determine the right bolt circle for your particular application from the Weld racing catalog.

Moving on to the more common five-lug layout, you no longer have perfectly opposing lugs to measure. But a couple of methods for determining the bolt circle exist. One is to measure from what would be the opposing bolts, and by adding 1/4-inch, you’ll arrive at your bolt circle. If you want to try another method or just simply check your work, you can also determine the bolt circle by measuring from the center point of one bolt to the bottom edge of one of the opposing bolts.

To learn more, including calculations for metric bolt circles and a look at tools that you can use to make measuring not only the bolt circle of the hub but also of the wheel a cinch, check out this and other videos over on the Weld Racing video channel. For more information on Weld Racing and it’s industry-leading line of wheels and accessories, log on to

Also check out this video on how to measure back spacing!

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About the author

Andrew Wolf

Andrew has been involved in motorsports from a very young age. Over the years, he has photographed several major auto racing events, sports, news journalism, portraiture, and everything in between. After working with the Power Automedia staff for some time on a freelance basis, Andrew joined the team in 2010.
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