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Box calculator

Package Size Calculator

Estimate the finished dimensions a carrier may measure after adding protective space around the product. Use external dimensions for shipping calculations.

Live calculator

Calculate a padded package size

CALCULATES LOCALLY · NO UPLOAD
Clearance / padding per side
FORMULA
Internal box = Product + (2 × padding per axis)

External estimate adds two wall thicknesses per axis.

SUGGESTED INTERNAL SIZE-
External package estimate-
Internal volume-
Added clearance volume-
Confirm the carton manufacturer’s internal dimensions and pack a physical sample before ordering production quantities.
Method

How this calculation works

Measure the sealed package at its extreme points before buying the label; real packed dimensions can differ. ParcelCal runs the calculation in your browser; no package or shipment information is uploaded.

FORMULA
External package = Product + two-sided padding + two wall thicknesses

Measure the sealed package at its extreme points before buying the label; real packed dimensions can differ.

Worked example

From item to shipping dimensions

  1. 1.Product: 10 × 7 × 4 in
  2. 2.Padding: 1 in on all sides
  3. 3.Board allowance: 0.25 in per wall

Estimated external package: 12.5 × 9.5 × 6.5 in.