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Dimensions and units
The unit control changes the display; the dimension definition tells you what physical boundary to measure.
Reviewed October 27, 2026
Read the model's definition
The tuck box uses approximate inside targets with a simplified thickness adjustment. The tray and polygonal prisms use fold-line measurements. A sleeve starts with the object's cross-section plus clearance, and an envelope starts with the insert and edge allowance. Pillow fields describe flat panels and curves.
For the two-piece box, the base length and width are inside targets, while base and lid wall heights are crease-to-cut distances. Do not interpret every height label as a guaranteed internal cavity.
Switch between mm and inches
One inch equals 25.4 mm. Changing units converts the display and must preserve the stored physical size. For example, 100 mm is approximately 3.937007874 in. Rounded display text is for readability; it should not become a new measurement unless you deliberately edit the input.
Enter plain numeric values in the displayed unit. Localised number formatting is used for results, while project JSON retains machine numbers and the versioned unit protocol.
Correct a field without losing the project
An empty field, nonfinite number or value outside the model's limits cannot produce a new valid result. The interface identifies the field and explains the permitted change. Some constraints depend on neighbouring dimensions, such as a glue tab fitting the wall.
If height is 0, the prior valid preview may remain for reference with a clear label and download is disabled. Correct the current value or restore the previous dimensions before exporting.
Sources and methods
Ready to make something?
Set the dimensions. Check the folds. Make a small test box.