Blueprint scale conversion calculator
Enter a measurement from your drawing and select the scale — get the real-world dimension instantly. For all common architectural and engineering scales.
The most common print error is wrong scale
Most blueprint printing errors come from incorrect scale.
Revit Fit to Paper and AutoCAD model space exports silently destroy scale accuracy. We verify scale before printing every order.
Important
This calculator assumes your print is at the correct scale.
Revit and AutoCAD can export PDFs at the wrong scale even when the title block shows the correct notation. Use our free scale checker to verify your PDF measures correctly before ordering.
Common architectural scale reference
| Scale notation | Scale factor | 1 inch on drawing = | 1/4 inch on drawing = |
|---|---|---|---|
| 1/16" = 1'-0" | 1:192 | 16 feet | 4 feet |
| 3/32" = 1'-0" | 1:128 | 10'-8" | 2'-8" |
| 1/8" = 1'-0" | 1:96 | 8 feet | 2 feet |
| 3/16" = 1'-0" | 1:64 | 5'-4" | 1'-4" |
| 1/4" = 1'-0" | 1:48 | 4 feet | 1 foot |
| 3/8" = 1'-0" | 1:32 | 2'-8" | 8 inches |
| 1/2" = 1'-0" | 1:24 | 2 feet | 6 inches |
| 3/4" = 1'-0" | 1:16 | 16 inches | 4 inches |
| 1" = 1'-0" | 1:12 | 1 foot | 3 inches |
Hub: Accuracy & Scale
Scale questions
At 1/4 inch = 1 foot scale, every quarter inch on the drawing represents one foot in the real building. A measurement of 2.5 inches on the drawing equals 10 feet in reality (2.5 ÷ 0.25 = 10). This is one of the most common scales for architectural floor plans and elevations.
The most common cause is PDF export settings. Revit's Fit to Paper option scales drawings to fit the paper size — the title block still shows the correct scale notation, but the print will not measure at that scale. AutoCAD model space printing produces similar errors. Use our free scale checker to verify your PDF before ordering prints.
Wrong-scale prints cause permit rejection — a permit reviewer places a ruler on the drawing and the dimensions don't match the title block notation. They also cause fabrication errors when components are built from incorrect measurements. At 97% scale (a common Revit export error), a 20-foot dimension on the drawing measures as 19.4 feet on the print.
Use our free scale checker at azulprints.com/blueprint-scale-checker. Upload your PDF and we detect the actual print dimensions and compare them to the scale notation in the title block. You can also print a test page and measure a known dimension with a scale ruler. If the measurement doesn't match what the title block states, your PDF has a scale error.