With an app using org.kde.desktop theme & using a Combobox component. rightPadding doesn't include the width of the indicator. If for example I want to size my ComboBox to the width of the largest element of the list, then I set the width of the combobox to the "largestTextWidth" + leftPadding + rightPadding When using themes like Universal, Default or Material... this works nicely. Actually they include the width of the "indicator" in leftPadding/rightPadding. But with org.kde.desktop it's incorrect. This is on KDE with Breeze theme (same problem with other themes, like QtCurve, but probably only Breeze is expected to be supported anyway)