How to draw a floor plan to scale

Separate three meanings of scale

Real dimensions describe the room. Drawing scale describes the ratio between a drawn length and the real length. Zoom only changes how large the drawing looks on your screen. Zooming in does not make a wall longer.

For a paper drawing at 1:50, a 4000 mm wall occupies 80 mm on the page: 4000 ÷ 50 = 80. At 1:100, it occupies 40 mm. The dimension label should still say 4000 mm, because it describes the room rather than the sheet.

A scale conversion table you can check

The imperial architectural scales above are 1:48 and 1:96, not exact equivalents of 1:50 and 1:100. Use the actual ratio throughout a drawing.

Build the room in real dimensions

For an image background, use the calibration tool on two points whose real distance you know. Select a second known distance to check the result. One calibration cannot repair perspective distortion or different horizontal and vertical stretching.

1. Collect the internal measurements and openings before drawing.
2. Draw the room outline in FloorDraft, then select a wall and enter the real length in millimetres.
3. Check wall thickness and internal face-to-face distances. A wall centreline length is not automatically the clear room width.
4. Add doors, windows and furniture at their measured sizes.
5. Use dimension annotations to check the distances that matter to your layout.

Catch unit mistakes with one reference length

A 3 m wall is 3000 mm or 300 cm. If a CAD recipient reads a length of 3 as millimetres, the drawing is 1000 times too small. Include the export unit in your handoff and ask the recipient to measure that wall.

FloorDraft fits the PDF drawing onto the page for viewing. To print at 1:50 or another measured scale, export DXF, set the print scale in CAD, and check a reference length on the printed sheet.

Questions