What this calculator answers
What minimum inside length, width, and height fit this product once cushioning is added on each side?
Formula
Inside dimension = product dimension + (cushioning × 2) on each axis. Measure packed longest, widest, and tallest points in inches.
Worked example
A 10 × 6 × 3 in candle with 1 in cushioning on each side needs 12 × 8 × 5 in inside. Round up to a stock box.
Limitations
Does not choose ECT grade, mailer vs box, or dimensional-weight cost. Confirm manufacturer inside dimensions.
FAQ
Do I add padding once or twice?
Twice per axis—both sides of the product.
Related decisions
How to take the inches: how to measure a product. Strength stamp: ECT vs burst. Billed size: dimensional weight calculator. Then price the kit: packaging cost.