Architectural Scale Converter
Convert between real-world dimensions and what they measure on paper, across US and metric drawing scales.
How scale works
A drawing scale is a ratio between paper and reality. 1/4" = 1'-0"
means a foot of building is drawn as a quarter inch — a 1:48
ratio. Metric drawings use the ratio directly: 1:50 means one
unit on paper is fifty in reality.
Choose a direction and a scale, then enter a dimension in any format. The converter handles US scales (1/16" to 3") and metric ratios (1:5 to 1:1000).
Frequently asked questions
What does 1/4" = 1'-0" mean?
A quarter inch on paper represents one foot (12 inches) in reality. Because 12 ÷ 1/4 = 48, that drawing scale is the ratio 1:48.
How do I convert an architectural scale to a metric ratio?
Divide the real length by the drawn length in the same unit. 1/8" = 1'-0" is 1:96, 1/4" = 1'-0" is 1:48, 1/2" = 1'-0" is 1:24, and 1" = 1'-0" is 1:12.
What is 1:50 scale in imperial terms?
1:50 means one unit on paper equals fifty in reality. It falls between the imperial 1/4" = 1'-0" (1:48) and 3/16" = 1'-0" (1:64) scales — close to a quarter-inch scale but not identical.