Bags made with a box base have been around for a LONG time, call them box-bags, bag-boxes, box-baggies - whatever you choose.
They are an easy project - but there is some mathematics involved and each time I make one I am asked for the dimensions and size of card stock and designer paper needed.
So, with the help of one of my awesome brothers here's a table to use to work out the dimensions of card stock and designer paper you need to create baggies like these in the pictures below...you can see I made three different sizes, that's just a few of the sizes you can make :)
And, below that a video showing you how to make it.
Cut your base cardstock at whatever the 'Cut Card Width' and 'Cut Card Breadth' gives you.
Score using the measurements given.
Lastly the length of designer paper needed is given.
No height is given as that's a personal preference - you can make the bag any size you wish :)