Set the page scale

Every measurement depends on the page scale. Until it's set, the status bar shows Scale: Not set and quantities can't be trusted.

Option A — Set the scale from the title block (fastest)

Every page thumbnail carries a Set scale chip (bottom-right, in Page Preview and Page List).

1. Click Set scale on the page.
2. In Set page scale — "Type in the scale in the provided format or pick from the list below" — either pick a common scale from the list (1/4" = 1'-0", 1/8" = 1'-0", 3/16" = 1'-0", 1" = 20', 1:48, …) or type your own in the same format.
3. Click ✓. The chip now shows the scale, and so does the status bar.

Option B — Calibrate from a known dimension (most accurate)

1. Open the page and click Calibrate Scale in the toolbar (the compass icon).
2. In Calibrate scale, keep Horizontal and Vertical ticked (or untick one to calibrate a single axis) and click Calibrate.
3. Click two points a known distance apart — a dimension string, a grid line spacing, or a door you know is 3'-0".
4. Type the real distance and confirm.

If a sheet is stretched unevenly (common with scans), calibrate the horizontal and vertical axes separately — tick only one axis, calibrate, then repeat for the other.

Option C — Accept the AI-detected scale (Pro)

On Pro, Page name & scale reads the scale from every sheet — see Read sheet names and scale. A thumbnail chip and a tooltip AI-detected scale — click Apply to calibrate appear. Click Apply, tick "I understand and will verify it before taking measurements", and confirm.

Always verify: draw a quick Measure line over a printed dimension and check the number matches.

Check a scale any time

Use Measure (M) to click two points and read the distance in the current scale. Wrong? Recalibrate — existing shapes on the page are recalculated with the new scale.

Per-page scales

Scale is set per page. Set it on each sheet you measure; the Page Preview chip shows Set scale on pages that still need it.