To change the project units, open the main menu dropdown and go to
Project → Units. We currently support feet and decimal inches, millimeters, and meters. The Arcol default for project units is feet.You may change the project units at any time and all existing units in the project will update automatically. Our inputs also support entering any unit you want regardless of the project units (eg. if project units are feet, you can still enter something like
5m when drawing a line and the conversion to project units will be done automatically).