Ordering custom boxes without seeing the flat sheet first is a guessing game. PackPaa’s free box dieline calculator removes that guesswork. Enter your box’s length, width, and height, and instantly see a print-ready cut sheet — complete with cut lines, fold lines, flap depth, and glue tab — calculated using standard slotted-box specifications.

Unlike static size charts, this tool updates live as you type, so you can test different dimensions and immediately see how they affect your flat sheet size and material usage. No design software, no waiting on a quote, no packaging engineering degree required.

Once you’re happy with the layout, download it as an SVG for your design team, print it directly as a reference sheet, or copy the dimensions to share with our team for a fast, accurate quote.

Whether you’re packaging cosmetics, bakery goods, retail products, or shipping mailers, getting the flat sheet size right the first time saves on material costs and reprints. Try the calculator below, then reach out to PackPaa for pricing on your custom corrugated or mylar packaging.