How to make a scale for a drawing?
Pick a ratio between paper and real distance, such as 1" = 20' on a civil site plan or 1/4" = 1'-0" on an architectural plan, then draw every dimension at that ratio. Add a bar scale, a line marked in real units, so the drawing still measures correctly after it is enlarged or reduced.
Engineering and architectural drawing scales
Engineering scales set one inch to a round number of feet. Architectural scales set a fraction of an inch to one foot.
| Scale | Type | 1 inch on paper equals |
|---|---|---|
| 1" = 20' | Engineering | 20 feet |
| 1/4" = 1'-0" | Architectural | 4 feet |
| 1/8" = 1'-0" | Architectural | 8 feet |
Draw a bar scale for a drawing
At 1" = 20', draw a 2-inch line and mark it at 0, 20 and 40 feet, with the ratio written beside it. A half-size print, such as 22 × 34 reduced to 11 × 17, keeps a true bar scale, but its written 1" = 20' now reads 1" = 40'.