Modern Boxes, a US custom packaging company serving small and growing brands, has launched a free box size and dimensional weight calculator aimed at businesses that order packaging in low quantities.

The tool addresses a problem that quietly costs small brands money on every order. Carriers price parcels on whichever is higher, the actual weight of the shipment or its dimensional weight, which is calculated from the size of the box. A box that is larger than it needs to be is charged as though it were heavy, even when the product inside is light. For a brand shipping a few hundred orders a month, the difference adds up quickly.

The calculator asks for product length, width and height, then returns three things. First, the recommended internal box size, with clearance adjusted for a snug, standard or padded fit depending on whether the product needs tissue, foam or an insert. Second, an approximate flat blank size, which is the size of the sheet before the box is folded and one of the factors that drives material cost. Third, the dimensional weight using both the divisor common to US domestic services and the divisor used by many international services.

Users can enter their actual parcel weight to see which figure a carrier would bill on, and the tool works in both inches and centimetres.

The company has been deliberate about the limits of the tool. The results are presented as planning figures rather than production specifications, because the exact blank size depends on board thickness, box style, tuck depth and glue flap allowances, all of which are confirmed when a dieline is prepared.

Modern Boxes produces custom printed packaging including mailer boxes, rigid boxes, cosmetic cartons, food safe boxes and kraft packaging, with a 100 unit minimum order, two to three day production and free design support. The company works primarily with startups and small product brands that cannot commit to the several thousand unit minimums common elsewhere in the industry.

The calculator is available at modernboxes.org/box-calculator and is free to use without registration.