Been measuring for curtains and find that the 228cm of ready mades are too long. 228cms seems the standard drop for floor lenght.
My entire drop for a floor length curtain from the coving to the floor is 225cms.
Without coving the ceiling height would be another 5-6 cms.
I never thought we had a low ceiling- it's a modernish house. I've got 19cms above the top of the doorframe to the ceiling.