Manual Scale should be used when the printed or stated scale in a plan file cannot be trusted. Manual Scale allows you to define scale by measuring known distances directly on the drawing. Instead of relying on a printed scale, you identify real-world dimensions and use them to calibrate the sheet.

When you should use Manual Scale

Use Manual Scale in the following situations:

• The plan file is a scanned drawing or image.
• The PDF has been resized, compressed, or distorted.
• The drawings were received as photos or image-based PDFs.
• The printed scale on the drawing is unclear, missing, or inconsistent.
• The drawing dimensions do not match expected measurements when using Standard Scale.
• You are unsure whether the PDF was generated directly from CAD or BIM software.

When Manual Scale is not recommended

Manual Scale may not be the best option when:

• The PDF is a vector-based drawing exported directly from CAD or BIM.
• The drawing includes a clearly defined and reliable printed scale.
• All sheets were created at the same known scale and can use Standard Scale instead.

Best practices when using Manual Scale

To get the most accurate results with Manual Scale:

• Use clearly labeled dimension lines whenever possible.
• Choose long, straight dimensions to reduce error.
• Verify both horizontal and vertical measurements.
• Avoid using short or angled dimensions for calibration.
• Recheck scale if measurements do not look correct.

Manual Scale vs Standard Scale

Standard Scale applies a fixed scale value to the sheet, while Manual Scale calibrates the drawing using known distances. If Standard Scale produces unexpected results, switching to Manual Scale is often the safest option.