Carriers may charge by dimensional weight: the space the parcel occupies relative to its actual weight. UPS uses this approach for packages that are large relative to their weight. That makes packaging design a commercial decision.
Request shipping estimates using the finished packed dimensions. Compare those with an alternative that removes unnecessary space while protecting the product. Use the intended shipping service and actual destinations in the comparison.
Compare packaging cost, packing labor, shipping charges and damage performance. A cheaper box can create a more expensive shipment. A smaller box can also create damage if protection is compromised.
Check the alternative through appropriate packing and transit tests before adopting it. Approve the packaging and delivery economics together.
Reference: UPS β Shipping Dimensions and Weight