Guide · measurements
How SVG units become DXF scale.
The root SVG viewport establishes physical scale. Path coordinates alone do not say whether a drawing is ten millimeters or ten inches wide.
Canvas and artwork are different
The SVG canvas is the root viewport described by width, height, and viewBox. Artwork bounds are the tight bounds of exportable paths inside that canvas. Empty margins can make the two sizes very different, so the converter reports both.
Physical root units
Root dimensions using mm, cm, Q, in, pt, or pc carry a physical meaning. The converter preserves that scale and records whether each axis was explicit or derived from a viewBox aspect ratio.
Pixels and unitless dimensions
SVG follows CSS absolute-length rules: 96 px = 1 in = 25.4 mm. A root width="96" or width="96px" therefore resolves to 25.4 mm. The result includes an INFERRED_CSS_PIXEL_SCALE information diagnostic so the assumption stays visible.
A viewBox is not a ruler
A viewBox="0 0 100 50" defines a coordinate rectangle and a 2:1 aspect ratio. Without a trustworthy absolute root width or height, it does not define a physical size. The converter returns a normal “measurement needed” state and asks for artwork width or height.
If you set artwork width to 100 mm, the converter scales the tight artwork bounds to 100 mm and preserves their aspect ratio. It does not resize an invisible page margin to 100 mm.
DXF output units
The converter writes R2000 DXF and sets $INSUNITS to millimeters or inches. Some importers still apply their own unit settings, so inspect the reported size in the target CAD/CAM application before fabrication.