Printing dimensions

if I print a tescube of 20x20x10 and an inner diameter of 10 mm , the outer dimensions are accurate to 0.1 mm but the inner dimensions are incorrect 9,25mm instead of 10 mm how can I fix this

I have the identical problem.
Initially I downloaded a calibration cube from but being unsure of its dimensions, I made made own, with the same result. Only the inner “hole” is wrong and too small, the outer dimensions are prety much what I would expect.
I look forward to an answer.

I’ve had the same. I had put together a little test piece, to check dimensions over a range of outer & inner shapes, but it’s a consistent difference. (

I now tend to compensate my designs, where I need to, with “best estimates”. That solves the problem - for my K8400 printer, that is.

It appears to be a phenomenon caused by slicer software? A description can be found here:

What I also recently found, is this description on Thingiverse, from “pcdangio”, that also includes an Excel spreadsheet with statistical details as measured on his printer. You can use this spreadsheet & his instructions to determine your own details.

Hope this helps?

Harry D.