Two ways to set scale
Preset: choose the scale printed on the sheet, such as 1/4" = 1'-0" (architectural, 1:48), 1" = 20' (engineering, 1:240) or 1:100 (metric). A preset is only right if the PDF is still at its original paper size.
Calibrate: draw a line over a dimension you know — a dimension string, a grid spacing, or a standard 3'-0" door — and enter its real length. This works even if the drawing was shrunk to fit letter paper or exported at an odd size.
Common architectural scales
| Scale | Ratio | Typical use |
|---|---|---|
| 1/8" = 1'-0" | 1:96 | Large floor plans, site layout |
| 1/4" = 1'-0" | 1:48 | Residential floor plans |
| 1/2" = 1'-0" | 1:24 | Enlarged plans |
| 1-1/2" = 1'-0" | 1:8 | Details |
Check before you measure
After setting the scale, measure another dimension that is printed on the sheet. If the plan says 24'-0" and you get 23'-11", you are fine; if you get 18'-0", the PDF was resized and you should calibrate instead. FreeTakeoff shows the scale for the current page at the top-left of the viewer so you never measure an unscaled sheet by accident.
Watch for NTS and mixed scales
Sheets marked "NTS" (not to scale) cannot be measured. Sheets with several details may use several scales; measure each detail on a separately calibrated page or skip it.
FAQ
Why does my PDF measure wrong at the printed scale?
The PDF was probably reduced (for example from 24x36 to 11x17). Calibrate from a known dimension instead of using the preset.
What is 1/4 inch scale as a ratio?
1/4" = 1'-0" is 1:48 — one quarter inch on paper equals 48 quarter inches (one foot) in reality.
Can each page have its own scale?
Yes. FreeTakeoff stores the scale per page, and you can copy one page's scale to all pages.