I’m replacing the rim on my rear wheel and the online calculator tells me I need 272 mm spokes. My current ones are 274 mm with 16 mm nipples, do you reckon I could get away with just using different length nipples? And if so, would it be 14 or 18 mm nipples I’d need?

In theory but what length nipples did you put into the calculator?

Are the rim erd’s the same?

4 mm difference in ERD, the calculator is based on 14 mm nipples but spat out the right number for the current (broken) rim (274 mm).

Not if the calculator’s saying 272mm with 12mm nipples (as they normally use in their calculations)

The fun kind??? 🙄

Guess that depends on your definition of fun!