Scale Converter for Drawings, Plans & Models
Convert a measurement on a scaled drawing, map or model to its real size, and back. Architectural (1/4" = 1'-0"), engineering, metric (1:50, 1:100), model and map scales, or any custom ratio.
How Architectural Scale Works
A drawing scale tells you how a measured distance on paper relates to the real building. The architectural scale 1/4" = 1'-0" means every quarter-inch on the drawing equals one foot in reality — a ratio of 1:48. Engineering scales like 1" = 20' work the same way (1:240), and metric drawings state the ratio directly, such as 1:50 or 1:100.
To scale up from a drawing, multiply the measured distance by the scale factor. To scale down a real dimension for plotting, divide it by the factor. This converter does both at once for any common scale, so you can read drawings or set up a sheet without a physical scale ruler.
Frequently Asked Questions
What does 1/4" = 1' scale mean?
It means a quarter inch on the drawing represents one foot in real life. Because one foot is 48 quarter-inches, the drawing is at a 1:48 ratio — so a 6-inch line on paper equals 24 feet.
How do I convert an architectural scale to a ratio?
Divide 12 inches (one foot) by the drawing measurement in inches. For 1/8" = 1', that's 12 ÷ 0.125 = 96, so the ratio is 1:96. The converter shows the ratio for every scale you select.
Can I convert between metric and imperial scales?
Yes. Enter your measurement in inches or millimeters and read the real-world result in both feet-inches and meters. Scale ratios like 1:50 are unit-independent, so the same factor works for both systems.
From Sketch to Clean Plan, or to a Measured DXF
These utilities pair with our AI tools: redraw a sketch or photo as a clean, labeled plan here, or design a measured plan with PDF and DXF for AutoCAD in Plan Chat (same account).