working out crate size for flatpack

[Neville Bastian]

Has anyone worked out how to create a box based on the parts cut from Ecabinets. Seem to be doing a few flatpacks of late and our normal knee jerk action is stack them on a guessed size bottom 16mm particleboard and when it reaches its safe lifting height create box 2 if required.Cut sides to height required.
This seems a bit backward when I know the square meters and I know the weight and part sizes. Have thought maybe a spreadsheet but thats not one my strengths. How do others do the box calculation?
Regards

Neville