[DuoMaxwell007]

Today I measured one of my wheels and it came out to 21in, so I looked up a video and someone did the same thing and measured 19in then then goes to say "if yiu got this then you did it wrong it's supposed to be measured this way and as you see you now get a measure of 18... these are 18in wheels) sooo since I measured my wheel wrong and got 21 is it safe to say I have 20in wheels? (They're the stock oem on a 2017 camaro 2LT)

[ctrlz]

Just look at the tires and see what the number is after the "R".
R19 is 19" wheels
R20 is 20"

other than bragging rights, the main reason to know wheel size is for tire shopping.

[CalgaryZL1]

Originally Posted by ctrlz

Just look at the tires and see what the number is after the "R".
R19 is 19" wheels
R20 is 20"

other than bragging rights, the main reason to know wheel size is for tire shopping.

Biggest question is are you talking about the actual wheel diameter which is the metal part or outer diameter of the actual tire? Because if you measure a 21 inch wheel you’re measuring a donk. all kidding aside, the wheel will measure 21 to 21.5 outer edge diameter for a 20” wheel

[ctrlz]

Originally Posted by CalgaryZL1

That is actually wheel size that the tire fits and not the actual outer diameter of the tire big difference

I think he's trying to figure out his wheel size, not rotational diameter of the tires.

[RamAir02]

Originally Posted by ctrlz

Just look at the tires and see what the number is after the "R".
R19 is 19" wheels
R20 is 20"

other than bragging rights, the main reason to know wheel size is for tire shopping.

Yes, look at your tires OP.

Typical format is Pxxx/yyRzz where

x = Tire Width in Millimeters

y = Tire Aspect Ratio (Height/Width)

z = Wheel Diameter in Inches

e.g. P305/30/R19 is a 305mm wide tire, 30 series aspect ratio, 19 inch wheel

[Msquared]

Guys, I'm sure if the tires were still on these wheels then he would have figured out to reference their specs on the sidewalls. The wheel diameter is measured at the surface for the tire bead seat, not the absolute outside edge of the wheel (rim edge). Likewise, width is also measured inside the bead seat rather than the very outside dimension of the rim edge. Also, every OEM wheel I've seen also has the dimensions (diameter, width, offset) stamped on the back somewhere. I am sure the OP's wheels are 20" diameter.