AutoCAD TIP – Calculate values without the Calculator Function!

By Dennis Collin

For many years AutoCAD has had several calculator tools. This can be useful when working out unknowns within a drawing to something straightforward like an enclosed area. The Quickcalc function has been in AutoCAD since 2006 and I often point users to this environment as it possesses a useful Units convertor, like Square Feet to Square Metres, which can save users a lot of painful number crunching.

However, there are other ways to calculate values without the Quickcalc function. This can be directly from the (full) AutoCAD command line.

The format is - (Expression<SPACE> value<SPACE> value)

E.g.        (+ 2 2) returns the value 4.

               (* 2 4) returns the value 8.

This method works very similar to how formulas are used in Excel. For example… (+ (* 3 2) 1) yields 7. Also, the expression (* (+ 2 3) 2) yields 10, as AutoCAD will evaluate the inner parentheses first.

Since the command line utilises Lisp, this command line method of evaluating numbers is not available for AutoCAD LT. Although for most users the newer Quickcalc function with its graphical interface will provide a more efficient workflow.