SVG imports at the wrong size
Measure a known feature first, then separate page dimensions, path bounds and receiver settings. A visual match does not prove the physical size is correct.
Compare the expected physical dimension with the imported path bounds. Check the SVG root width and height, viewBox, transforms and any receiver setting that interprets CSS pixels or document units. Correct the source on a copy, reimport into an empty document and measure again; do not scale by eye.
Find which size contract changed
An SVG can carry a page width and height, a viewBox coordinate system and path geometry with transforms. These values can agree, disagree or omit physical units. The receiving application may apply its own px, dpi or unit rule.
The table separates an SVG diagnosis from the DXF unit-label failure in the companion guide. This page gives a check sequence; it does not claim a universal import behavior for every editor or cutter.
| What you see | Inspect first | Boundary |
|---|---|---|
| Root width/height are px or absent | Record width, height and whether physical units are declared | A pixel value is not automatically a millimeter dimension |
| viewBox and page ratio disagree | Compare viewBox width/height with the page and path bounds | A correct aspect ratio can still have the wrong physical scale |
| Paths are inside transforms or groups | Inspect the transformed bounds in the source editor | Do not remove transforms without checking the geometry and master file |
| Only one receiver imports incorrectly | Compare that application’s SVG import and unit settings | One receiver result does not establish universal SVG behavior |
Diagnose the SVG in five steps
Write down a known dimension
Use a measured feature or intended width, such as 100 mm. Record the source unit and the receiver unit before opening the file so a ratio can be calculated.
Inspect the root size and viewBox
Read the SVG root width, height and viewBox. Note px, mm, in or missing units, and compare the numeric page ratio with the viewBox ratio.
Check path bounds and transforms
Select the actual paths in an editor and inspect their bounds. Expand or preserve transforms deliberately; the page rectangle is not proof of the drawing’s physical size.
Import into an empty document and measure
Use the receiver’s documented SVG import setting, then select the geometry and measure the same feature. Compare both width and height instead of judging the canvas visually.
Fix the source and repeat the check
Edit a copy with an explicit physical size and a coherent viewBox, save it, reimport and measure again. Keep the original SVG and the receiver/version in the record.
A reference fixture with explicit bounds
The downloadable project fixture has a recorded 100 × 70 mm SVG and a matching calibration drawing. It is a size reference for the checks above, not a reproduction of every application’s SVG import rule.
Use the fixture to test whether your measurement process reads the drawing bounds, units and orientation consistently. The project has not recorded a native SVG import result for every target application.
Diagnose before rescaling
| Symptom | Next check |
|---|---|
| Both dimensions are uniformly too large | Calculate expected ÷ measured, then inspect px/unit interpretation before applying a uniform correction on a copy. |
| Width is right but height is wrong | Compare the viewBox ratio, path bounds and aspect-ratio preservation; do not stretch the artwork to hide the cause. |
| The page is right but the artwork is wrong | Inspect groups, transforms and the selected path bounds. The page rectangle may not match the drawing geometry. |
| Only one application is wrong | Record the exact application/version and its SVG import setting, then compare with a known-dimension fixture before changing the source. |
Continue with the related checks
Use the DXF diagnosis for declared DXF units and 25.4× failures, the format guide for a delivery choice, and the LightBurn guide for the recorded calibration import. Keep SVG and DXF measurements separate.
Sources and verification
The size contract follows the SVG specification and the receiving application’s published import settings. This page provides a diagnostic method and a bounded reference fixture; it does not report universal px/dpi behavior, arbitrary-file compatibility or a new native LightBurn SVG test.