Takeoff
3 min readCalibrating the page scale
When the OCR-detected scale is wrong, override it with two clicks on a known dimension.
The vector parser tries to detect scale from title-block text or a scale bar. Sometimes the title block is illegible or the scale is non-standard (1"=20'-0"). Override it manually:
- Open the document detail page and click 'Calibrate' in the toolbar.
- Click the start point of any known dimension on the plan (corner of a wall, end of a parking stall).
- Click the end point.
- Enter the real-world distance (e.g. 10' or 3.0 m).
- Click 'Save calibration'. The override is stored on the document and applies to every takeoff line derived from it.
Tip
Pick a dimension that's at least 4" long on the printed page — short reference lines amplify pixel-level error in the calibration math.