It depends: If you’re using StitchBuddy for macOS, there is a corresponding setting in the app‘s preferences: Changing the measurement unit requires a restart of StitchBuddy and you might want to consult its help about different ways to enter values.
StitchBuddy HD on iOS / iPadOS doesn’t support different measurement units, but works only with millimeters.
Please don‘t mind that I‘m moving this discussion into the „Tips & Tricks“ category…
