Ice-cream tub measurements

Now that the company side of the project is finished, I need to start on the packaging. My first thought was about the dimensions of the tub that the ice cream will be going in. After some trial and error I found what dimensions I would need to have a interior volume of 500ml^2. There is some error to this because the 'perfect' volume would 512ml^2 but because of the thickness of card that the tub is made out of it's close to no extra. After having this measurement I thought about how no ice cream tub is filled to the brim, so at the top there is a 1cm gap with no ice cream and at the bottom there is a 1cm high card square ring that acts as a small support to keep the tub off of the surface its placed onto.