Box dimensions converter
Convert a box size between inches, centimeters, millimeters and feet in one step, including fractional inches.
How it works
Packaging suppliers in the US quote boxes in inches, while most of the world uses millimeters or centimeters. Mixing them up is an easy way to order the wrong box, so convert every dimension before you send a spec.
The fractional result rounds to the nearest 1/16 inch, which is how most tape measures and US box specs are written. Keep the order the same when you convert: length × width × height. See how to measure a box if you're not sure which side is which.
Results are estimates based on typical industry values. Confirm final specifications with your supplier or carrier.
Frequently asked questions
How do I convert box dimensions from cm to inches?
Divide each dimension by 2.54. A 30 × 20 × 15 cm box is about 11.81 × 7.87 × 5.91 inches.
Should I round when converting box sizes?
Round product sizes up, never down, so the box is never too small. For box specs, most US suppliers work to the nearest 1/16 or 1/8 inch.
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