How do I set the scale without a ‘Known Length’?
If your image has a known length use the rule tool during image import.
If your image doesn’t have a known length, a drawing scale bar, or dimensions of any sort, but the plans scale is indicated (⅛ : 1′) you can calculate the drawing scale using the dimensions of the imported plan.
Check your PDF or Image against these common dimensions:
North American Loose Paper Sizes
SIZE – INCHES / MILLIMETERS
Letter – 8.5 × 11 / 216 × 279
Legal – 8.5 × 14 / 216 × 356
Tabloid – 11 × 17 / 279 × 432
Ledger – 17 × 11 / 432 × 279
North American ARCH Series Paper Size
SIZE – INCHES / MILLIMETERS
ARCH A – 9 x 12 / 229 × 305
ARCH B – 12 x 18 / 305 × 457
ARCH C – 18 x 24 / 457 × 610
ARCH D – 24 x 36 / 610 × 914
ARCH E – 36 x 48 / 914 × 1219
ARCH E1 – 30 x 42 / 762 × 1067
North American ANSI Series Paper Sizes
SIZE – INCHES / MILLIMETERS
ANSI A – 8.5 × 11 / 216 × 279
ANSI B – 11 × 17 / 279 × 432
ANSI C – 17 × 22 / 432 × 559
ANSI D – 22 × 34 / 559 × 864
ANSI E – 34 × 44 / 864 × 1118
International ISO 216 A-Series Paper Sizes
SIZE – INCHES / MILLIMETERS
A0 – 33.1 × 46.8 / 841 × 1189
A1 – 23.4 × 33.1 / 594 × 841
A2 – 16.5 × 23.4 / 420 × 594
A3 – 11.7 × 16.5 / 297 × 420
A4 – 8.3 × 11.7 / 210 × 297
A5 – 5.8 × 8.3 / 148 × 210
A6 – 4.1 × 5.8 / 105 × 148
A7 – 2.9 × 4.1 / 74 × 105
A8 – 2.0 × 2.9 / 52 × 74
A9 – 1.5 × 2.0 / 37 × 52
A10 – 1.0 × 1.5 / 26 × 37
Working in millimeters convert your indicated scale. Example;
⅛ : 1’ converts to 3.175mm : 304.8mm (every 3.175mm on the paper plan represents 304.8mm in the real world).
If the total width of the paper is 1067mm (ARCH E1 in this example). Multiply this by 304.8mm then divide by the 3.175mm to find the plans width of = 102432 mm.
Example:
3.175mm (paper) == 304.8mm (real world)
1067mm (paper) == x
So x = 1067 x 304.8 / 3.175
Returning to SketchAndCalc, import your plan. Using the scale tool draw across the entire width of the page and input your width of 102432 mm or equivalent 336.06 ft and submit.
Your drawing scale is now set!
