How to measure and read a bolt pattern
The PCD is the diameter of the circle running through the centre of every stud. For an even count you can measure straight across two opposite studs; for a 5-stud wheel there's no opposite stud, so measure the adjacent stud spacing and convert:
PCD = stud spacing ÷ sin(180° ÷ number of studs)
Inch patterns are just the same circle in inches — 5×114.3 mm = 5×4.5", 5×120.65 = 5×4.75". The pattern must match your hub exactly; unlike offset, it isn't something a spacer changes (a proper adapter can, but that's a different part).
FAQ
Is 5×114.3 the same as 5×4.5?
Yes — 114.3 mm is exactly 4.5 inches, so 5×114.3 and 5×4.5" are the identical pattern written in different units. Same for 5×120.65 = 5×4.75" and 5×127 = 5×5".
Can a spacer change my bolt pattern?
A plain spacer can't — it keeps the same pattern, just further out. Changing pattern needs a bolt-pattern adapter, which bolts to your hub pattern and presents a different one on its face. Check load rating and hub-centricity before using one.