Calculate sheet metal box blank dimensions, internal volume, surface area and estimated flat material requirements for a simple open-top box or tray.
For accurate production work, use your validated bend allowance from actual material and tooling data.
These are optional additions for joining and cutting. Set them to zero when your dimensions already include them.
Enter your box dimensions and calculate.
What type of box does this calculate? It is designed for a simple one-piece open-top sheet metal box or tray with four 90° side bends.
How is the box volume calculated? Internal volume is calculated as finished length × finished width × finished height.
Does the calculator account for sheet thickness? Yes. Thickness is included as a material input and is useful for validating bend geometry, although finished dimensions are treated as the dimensions you enter.
Why is bend allowance required? The material travels through an arc during bending, so the developed blank must account for the length consumed by each bend.
Can I calculate a box with a lid? The basic calculator estimates the open box. A lid requires additional geometry and material.
Can I use this for production? Use it as a preliminary engineering estimate. Production blanks should be checked against your actual bend tables, tooling, corner reliefs and fabrication method.