How to Measure a Caster

How to Measure a Caster

Casters can be used for a wide variety of applications, from being used in ovens to constantly being exposed to water. But just as important as it is to have the right caster for the right application, the right size caster will be the difference of having a working application to not working at all. Taking key measurements will ensure that the caster will fit for the application. The following are four areas to measure.

Measure Top Plate and Bolt Hole Pattern






The top plate of a caster is used to fasten a caster to a desired object. Since top plates come in different sizes, it is necessary to measure the location where the caster will be attached and the top plate that will be used. To do so, measure the outside to the outside of the top plate one way (length) and then repeat this on the perpendicular side (width).

To determine the bolt hole pattern size, measure in the same manner only this time measure the center of one hole to the center of the other (length), then repeat this to measure the width.

Measure Wheel Size






Two measurements are taken when measuring the wheel size, the diameter and the width. The diameter is measured with the wheel lying flat on its side, and with a measuring device measure from one side of the wheel to the opposite side. If the wheel is 8”, then the caster is considered a 8” caster.  It’s important to make sure the measuring device passes over the center of the wheel. This ensures that the measurement is centered and will be more accurate. To measure the width, stand the wheel upright and measure from the outside of one side to the outside of the other.

Measure Swivel  Radius






The swivel radius is important to know if swivel restrictions will be a factor. For example, when casters are attached to a cabinet there is often a skirt that runs along the bottom that hides the casters. If the swivel radius is too big and hits the skirt of the cabinet, then the casters will not be able to swivel the full 360 degrees. The swivel radius is measured by measuring from the center of the kingpin to the trailing edge of the wheel. This is best achieved when the caster is lying down on its side and a straight edge is used up against the face of the wheel.  The straight edge should be long enough to make contact with your measuring device. Where the straight edge comes in contact with the measuring device is the swivel radius measurement.

Measure Overall Height






The overall height is critical when the overall height of the object you are putting casters on is limited, or when you are replacing one caster out of a set of four casters. If the caster used to replace a caster has an overall height that is greater or smaller than the existing casters, then the object that has the casters fastened to it will be off level. Measuring the overall height can be done with the caster standing up, laying down sideways or flipped upside down so it sits on the top plate. Measure from the top plate to the bottom of the wheel.

We have an easy to use toggle menu on our caster category page that allows you to navigate to the caster options that match the measurements you need. 

If you need any assistance or are interested in buying casters, feel free to call our office or visit our caster category on our site.


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