Calibration (Scale)

The act of telling your takeoff software how many on-screen inches equal one real-world foot.

Calibration sets the scale of a PDF sheet so that on-screen measurements correspond to real-world dimensions.

Without calibration, every measurement is in screen pixels — useless for estimating.

Click the start of a known dimension on the plan. Click the end. Type the real-world distance. The viewer computes the scale factor.

Most plans have a stated scale (1/4" = 1'-0", 1/8" = 1'-0", etc.) but PDF compression and printing can change the actual scale. Always verify against a known dimension on the sheet.

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