The quickest way to know your wheel center cap size is to measure the wheel’s hub bore and the cap’s outer diameter, or to look up the OEM part number for your vehicle and wheels.
Center caps are cosmetic inserts that cover the wheel hub opening and help protect bearings from dirt. Sizes vary by make, model, and whether you use OEM wheels or aftermarket rims. This guide walks through reliable methods to identify the correct size and how to measure it accurately.
Key measurements to know
To shop for the right cap, you’ll need to know two core dimensions. The following details help you compare options and avoid ill-fitting caps.
- Hub bore (center bore) diameter of the wheel — the hole through which the vehicle’s hub fits. The center cap must align with this opening.
- Center cap outer diameter — the visible diameter of the cap that sits flush with the wheel face. This determines whether the cap fills the opening neatly.
- Cap mounting style and compatibility — caps may clip in, press in, or rely on the hub’s core diameter; ensure the cap matches your wheel’s mounting design and your vehicle.
With these measurements, you can compare OEM caps, aftermarket options, or universal caps to find a good fit.
How to measure or verify your size
If you want to confirm the size yourself, follow these practical steps to get precise results.
- Find the hub bore diameter for your wheels. Check the vehicle’s owner's manual, the wheel specification sheet, or the manufacturer’s website; you can also measure the center hole on the wheel itself using calipers or a ruler.
- Measure the center cap’s outer diameter. Remove the existing cap if possible and measure the cap’s full width across the front edge with a tape measure or calipers.
- Check the cap’s mounting details. Determine whether the cap clips, screws, or presses into place, and verify whether it’s designed for hub-centric or lug-centric wheels.
- Look up OEM part numbers or wheel manufacturer specs. Use the vehicle make/model, wheel size, and year to search catalogs from the wheel or car maker, then match the cap size or part number to what you need.
- If in doubt, consult a dealer or reputable wheel shop. Show them the wheel or current cap, and they can confirm the correct size or order the exact OEM replacement.
When measuring, accuracy matters. If you can’t find a fitment match, consider professional guidance or verify whether a universal cap is compatible with your wheel’s mounting system.
Additional considerations
Beyond size, center caps vary by brand, finish, and attachment method. Some aftermarket caps mimic OEM designs, while others are universal and require careful fitment checks. If you’re restoring an older vehicle or unique wheels, keep an eye on part numbers and compatibility notes from the manufacturer.
Summary
Determining your wheel center cap size comes down to two core measurements: the hub bore diameter and the cap’s outer diameter, plus understanding how the cap attaches. Use manufacturer specs, measure the wheel and cap carefully, and verify with a dealer or wheel retailer if needed. With the right size, your wheels will look complete and function as designed.