Architectural Scale Calculator

A drawing scale calculator built around the architect's and engineer's rules rather than a bare ratio. Pick the scale the way it is written on the sheet, 1/4 in = 1 ft, 1 in = 20 ft or 1:50, and it tells you which edge of the rule that sits on; measure a line and it returns the real dimension in feet and inches; give a real dimension and it returns the length to draw, rounded to the sixteenth and thirty-second you can actually read. A third action takes a building footprint and a sheet size and finds the largest standard scale that still fits. Scaling a printed drawing is a last resort, because sheets get reissued at the wrong size.