Free architectural scale tool
Convert real property measurements to drawing lengths, convert plan measurements back to real dimensions, or identify an unknown scale.
Enter the project measurements, then select Calculate. Nothing is uploaded or stored.
How to use the calculator
A drawing scale connects paper measurements with real property dimensions. The stated scale is only reliable when the sheet is printed at the intended size; “fit to page” printing or image resizing can change the effective scale.
Continue your permit planning
Calculation questions
These answers explain the planning calculation. Verify local definitions before using the result in a permit package.
Common scales include 1 inch = 10, 20, 30, 40 or 50 feet. The best scale depends on lot size, sheet size and required detail.
The PDF may have been printed using Fit, Shrink or another resizing option. Print at 100% or Actual Size and verify a known dimension.
Yes. Measure a line on the drawing and divide the known real length in feet by the drawing length in inches.
No. A permit-ready plan also needs accurate source measurements, labels, dimensions and the information required by the reviewing authority.
Need drawings, not just a calculation?
Send the property address, proposed project and any city checklist. We will confirm the drawing scope before you order.
Educational planning tool. Confirm local definitions and limits before permit submission.
