I cut this Birthday Box on my Cricut X, using the "Tags, Bags, Boxes n' More" cartridge. I saved the cut file, so that I can use it again. I was able to stuff a good amount of goodies in there. If you would like to use this cut file (and saving yourself some time in not having to fuss with the sizes yourself), you may do so by clicking here. Size is about 8.5" x 5.75" x 1.25". The sentiment was also cut on my Cricut X, using Lyrical Letters. I've added some sticker diamonds to each letter to jazz it up.
Be sure to scroll down to view the Hidden Kool Aid Barrel that I've decorated, also with the Cricut.