ScaleDraw
Open the board
An online scale ruler
A triangular scale ruler only works on paper, at the size the drawing was printed. On screen, drawings are zoomed and resized all the time. ScaleDraw does the scale ruler's job however big the drawing is shown.
How it compares to a scale rule
| Scale rule | ScaleDraw | |
|---|---|---|
| Works on screen | No | Yes, at any zoom |
| Scales available | The six or so printed on it | Any, including unknown scales from a known length |
| Areas | No, you do the sums | Yes, for rectangles and any shape you draw round |
| Units | Usually metric only | mm, cm, m, inches and feet |
Using it
Add the drawing
Drag a PDF, image or screenshot onto the board.
Set the scale
Press Calibrate and drag along a known length, or for a PDF at its true paper size, type the printed ratio.
Measure
Use Measure (M) like a scale rule: drag from point to point and read the real length.
Questions
Is zooming a problem?
No. The scale is stored with the drawing, so measurements stay right at any zoom.
Is it free?
Yes, the Free plan includes measuring one image and one PDF page per board.