Use arithmetic in a field

Type a sum instead of a number. Dimensions, point coordinates, extrude distances, blend sizes, all of them.

Worked examples

Type	Get	Use
25.4 * 2	50.80	Two inches
1.5 * 25.4	38.10	An inch and a half
120 / 3	40.00	Three equal divisions
40 / 2 - 3	17.00	Half, less a wall thickness
sqrt(40^2 + 25^2)	47.17	The diagonal of the plate
hypot(40, 25)	47.17	The same, more directly
2 * pi * 12	75.40	A circumference
50 * sin(30)	25.00	Trigonometry, in degrees
max(12, 8 + 3)	12.00	Whichever is larger
round(37.8)	38.00	To the nearest whole millimetre

Angles are in degrees throughout, matching what the angle fields display. sin(30) is 0.5.

Committing

Enter evaluates and commits. The field then shows the result.

A field that cannot be parsed turns red and keeps your cursor, so a typo is corrected in place. Clicking away from a bad expression abandons it and the field returns to the stored value.

What is kept

Both the number and the sum. The field shows 50.80 while idle and 25.4 * 2 when you focus it, so the intent survives and is editable. A small fx mark says the field carries one.

Typing a plain number over it drops the sum.

Point X and Y fields keep only the number. They are solver output, moved by dragging and by constraints, so a stored expression would be overwritten on the next solve.

Reference a value from several fields

Give it a name. A parameter is a named value that any field can be driven by, and changing it changes everything that names it.

plate = 40 in the table	The value, once
plate / 2 in a dimension	Half of it, and it follows
plate - 2 * wall in another	Whatever the relationship is

Constraints are still the better tool where the relationship is geometric. A Symmetric or Equal constraint survives dragging; an expression is recomputed only when the parameter behind it moves.

Full grammar

Expressions lists every operator, constant and function.