AutoCAD Scale Factor - Architecture Dictionary

AutoCAD Scale Factors

Use this scale factor chart to help you find a usable conversion factor for your CAD drawings 📐

Architectural

Drawing ScaleScale FactorViewport ScaleDecimal Scale
1/16" = 1'-0"1921/192 xp0.0625" = 1'-0"
3/32" = 1'-0"1281/128 xp0.09375" = 1'-0"
1/8" = 1'-0"961/96 xp0.125" = 1'-0"
3/16" = 1'-0"641/64 xp0.1875" = 1'-0"
1/4" = 1'-0"481/48 xp0.25" = 1'-0"
3/8" = 1'-0"321/32 xp0.375" = 1'-0"
1/2" = 1'-0"241/24 xp0.5" = 1'-0"
3/4" = 1'-0"161/16 xp0.75" = 1'-0"
1" = 1'-0"121/12 xp1" = 1'-0"
1 1/2" = 1'-0"81/8 xp1.5" = 1'-0"
3" = 1'-0"41/4 xp3" = 1'-0"

To convert an architectural drawing scale to a scale factor:

Select the desired scale, then invert the fraction and multiply by 12.

For example, if you choose 1/8" = 1'-0"

• Invert the 1/8 to get 8/1

• Multiply 8/1 by 12

• 8/1 x 12 = 96

• Scale Factor = 96

Engineering

Drawing ScaleScale FactorViewport Scale
1" = 10'-0"1201/120 xp
1" = 20'-0"2401/240 xp
1" = 30'-0"3601/360 xp
1" = 40'-0"4801/480 xp
1" = 50'-0"6001/600 xp
1" = 60'-0"7201/720 xp
1" = 70'-0"8401/840 xp
1" = 80'-0"9601/960 xp
1" = 90'-0"10801/1080 xp
1" = 100'-0"12001/1200 xp

To convert an engineering drawing scale to a scale factor:

Select the desired scale, then multiply the feet by 12.

For example, if you choose 1" = 20'

• Multiply 20 by 12

• 20 x 12 = 240

• Scale Factor = 240