Last updated: March 2026
Enter your item dimensions and we'll recommend the smallest standard box that fits — with room for packing material.
1 inch can be the difference between fitting and getting stuck.
“Checked my carry-on against 3 airlines before a trip. Saved me a gate-check fee.” — Frequent flyer
Measurements verified by the ItemFits engineering team · Our methodology
Standard sizes say it works — but your measurements are what matter.
Add 2 inches on each side of the item (4" total per dimension). This provides room for bubble wrap, packing paper, or foam. A 10×10×10" item needs a 14×14×14" box.
Common sizes: Small (12×10×6"), Medium (18×14×12"), Large (24×18×18"), Extra Large (24×20×24"). Most carriers also accept custom sizes up to 165" combined length + girth.