Originally Posted by Doering
Our wheel lugs turned out to be 3/4". All is well though!
Most SAE bolts and nuts you'll encounter go by the same rule of thumb
Bolt heads are measured to 1.5x the diameter of the bolt ie: 1/2" bolt equals 3/4" head.
Most full size nuts are the same as the bolt head +1/16"- 1/2" bolt equals 3/4+ 1/16" = 13/16".
There are more compact nuts, often called Navy nuts which measure the same as the bolt head, no 1/16" adder. They are not as common as the SAE sizes. Knowing this saves extra trips to the toolbox.