Expression Evaluator

Attach a unit suffix to any number and it converts on the spot: in, ft, yd, mm, cm, m (long forms like inches, feet, meters work too), plus the machinist shorthands " for inches and ' for feet. Units mix freely within one expression — 1in + 3mm is fine. A bare number takes your Settings → Preferred Units, so 10 means 10 mm in metric mode and 10 inches in inch mode, and the result always displays in your preferred units regardless of what you typed.

Angle inputs use the same machinery with deg and rad suffixes; a bare number is degrees, so 1.5708rad and 90 are the same angle.

Working in inches on a print dimensioned in millimeters (or vice versa), you never convert by hand — type the value as printed, with its unit, and JetCad3 does the arithmetic exactly. The one deliberate exception: the Scale tool's factor is unitless, so 2 always means 2×, not 2 mm.

The conversion works in both directions. Every length box in the 3D tools — Extrude, Sheet Metal, Fillet, Chamfer, the primitive shapes, and the rest — is labeled with the active unit (Height (mm)) and shows its value in your preferred units, whether the value came from a drag handle, an edit of an existing feature, or a remembered default. Leave a field and it tidies to a clean number in your units; an entry that can't be read is flagged red instead of being silently misread. Tool defaults remember the physical size, so a flange height saved in metric mode is the same height when you switch back to inches.