Guide • “calibrate scale pdf ipad”
How to calibrate scale on a PDF plan (iPad)
Accurate measurements start with calibration. Here’s a practical method that works for both scanned drawings and vector plans.
Step-by-step
- Pick a known dimension on the plan (e.g., a doorway width or a labeled segment).
- Zoom in so your taps land exactly on the endpoints.
- Select the calibration tool and tap the two endpoints.
- Enter the real-world length and choose the unit system (ft/in or m/mm).
- Confirm the scale and place a quick test measurement nearby to sanity-check.
Common calibration mistakes (and how to avoid them)
Using an ambiguous reference
Pick a dimension explicitly labeled on the drawing whenever possible.
Calibrating on the wrong page
If your PDF has multiple sheets at different scales, calibrate per page.
Not sanity-checking
Always place a quick test measurement on a second known dimension.