Sizing
Measure once. Ship right.
Dimension is the single biggest cost driver in DTC packaging. Here is how to size a box that fits the product, fits the shipping rate card, and does not waste money on void fill.
The fundamentals
Four numbers to know.
Interior vs exterior
Interior = product fits. Exterior = shipping rate. Confirm both before approving the dieline.
Void fill allowance
Plan for 0.25–0.5" of clearance on every axis for protective material.
Dim-weight pricing
Carriers price by `L × W × H / 139` — keeping the cube tight is real money.
Mailer vs shipping
Under 3 lb? E-flute mailer. Heavier or fragile? B/C-flute shipping box.