PJHTech PaperUse graph paper for a scale sketch
Choose what one square represents before drawing the first wall or object.
Convert one square
At 1:N scale, a length of 1 mm on the page represents N mm on the object. Multiply the printed square size by N, keeping the units the same.
| Scale | A 5 mm square represents | A 4 m length uses |
|---|---|---|
| 1:20 | 100 mm = 0.1 m | 40 squares = 200 mm |
| 1:50 | 250 mm = 0.25 m | 16 squares = 80 mm |
| 1:100 | 500 mm = 0.5 m | 8 squares = 40 mm |
Check that the sketch fits
An A4 portrait page with 15 mm side margins leaves 180 mm of width: 36 squares on a 5 mm grid. At 1:50 that spans 9 m. A 10 m wall needs 200 mm on the page, so use landscape or a smaller drawing scale.
Write the scale and at least one measured dimension on the sketch. For an object that needs accurate fabrication dimensions, use its dimensions rather than measuring a printout.
Do not mix inch and metric squares
A quarter-inch square is 6.35 mm, not 5 mm. At a chosen architectural scale of ¼ inch = 1 foot, one quarter-inch square represents one foot. The corresponding length ratio is 1:48, not 1:50.
Verify the printed grid
Print at Actual size or 100%. Ten 5 mm squares should measure 50 mm from line center to line center. If the result differs, correct the print settings before drawing to scale.