Box Sizes in CM: Centimeter Conversion Chart
Working from a centimeter spec? US boxes are sold in inches, inside dimensions. Convert with 1 inch = 2.54 cm (divide cm by 2.54), round up to the nearest stocked size, and you’re done. The charts below pre-convert the most common sizes.
Common box sizes: inches to centimeters
| Inches (inside) | Centimeters |
|---|---|
| 6 x 6 x 6″ | 15.2 x 15.2 x 15.2 cm |
| 8 x 8 x 8″ | 20.3 x 20.3 x 20.3 cm |
| 9 x 9 x 9″ | 22.9 x 22.9 x 22.9 cm |
| 10 x 10 x 10″ | 25.4 x 25.4 x 25.4 cm |
| 12 x 12 x 12″ | 30.5 x 30.5 x 30.5 cm |
| 14 x 14 x 14″ | 35.6 x 35.6 x 35.6 cm |
| 16 x 16 x 16″ | 40.6 x 40.6 x 40.6 cm |
| 18 x 18 x 18″ | 45.7 x 45.7 x 45.7 cm |
| 20 x 20 x 20″ | 50.8 x 50.8 x 50.8 cm |
| 24 x 24 x 24″ | 61.0 x 61.0 x 61.0 cm |
| 12 x 9 x 6″ | 30.5 x 22.9 x 15.2 cm |
| 16 x 12 x 6″ | 40.6 x 30.5 x 15.2 cm |
| 16 x 10 x 6″ | 40.6 x 25.4 x 15.2 cm |
| 15 x 12 x 4″ | 38.1 x 30.5 x 10.2 cm |
| 10 x 8 x 6″ | 25.4 x 20.3 x 15.2 cm |
| 24 x 18 x 12″ | 61.0 x 45.7 x 30.5 cm |
Bubble mailer sizes in cm
| Size code | Inches | Centimeters |
|---|---|---|
| #000 | 4x8" | 10.2 x 20.3 cm |
| #0 | 6x10" | 15.2 x 25.4 cm |
| #2 | 8.5x12" | 21.6 x 30.5 cm |
| #5 | 10.5x16" | 26.7 x 40.6 cm |
| #7 | 14.25x20" | 36.2 x 50.8 cm |
Full imperial charts: the box size chart and mailer size chart. Have a metric part spec instead? Try the part number lookup.
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Frequently asked questions
How do I convert box sizes from centimeters to inches?
Divide each centimeter dimension by 2.54. A 30 x 23 x 15 cm box is 11.8 x 9.1 x 5.9 inches - then round UP to the nearest stocked size (12 x 9 x 6 in this case) so contents still fit. US corrugated sizes are quoted as inside dimensions in inches.
Are US box dimensions inside or outside measurements?
Inside dimensions - the usable interior. If a cm spec you received is an outside measurement, subtract roughly 1 cm per dimension before converting, or size up one increment after converting.