I plan on buying satin ice fondant to cover a cake for a cake decorating competition. I was planning on making my own fondant but I think this would be easier and a lot less time consuming. I think I would rather spend some extra money and save some time so I can concentrate on decorating. I am stacking a 10, 8 and 6 and was wondering if the 5 lb tub of satin ice would be enough? I was looking at the 2 lb tub but I don't think it would be enough. I would rather have some extra leftover than not have enough.

This is a pretty accurate guide

http://www.wilton.com/decorating/fondant/fondant-amounts-to-cover-cakes.cfm

I am just really nervous that I will not order enough and then I am going to have no way to get more satin ice to cover the cake. What are the differences between satin ice and wilton's fondant?

Sorry I have never used store bought fondant. But the weights of the 2 fondants could not be that different. How high are your cakes? According to the chart you will need about 4.9 pounds of fondant if they are 4" high.

Some fondants you can roll thinner than others, so there will be a little difference there.

BUT these charts are used as guides, not as exact amounts. They have a little 'waste' built in, so unless you just way under order you should be okay.

What size/shape cakes are you making?

They are 10 8 and 6 inch rounds. I am assuming they are 4 inches high I think. The cake looks like this:

http://tinypic.com/r/dr5q85/7

6in round - 18oz
8in round - 24oz
10in round - 36oz

Total of 78oz divided by 16oz gives you 4.88lbs.

So a 5lb tub would be enough. If it is white fondant I would probably order a little extra, just in case you do have an issue. You can always store it for use later on.

Thank you!! I am now seriously debating on buying the wilton because I would hate to have something happen to the satin ice the night before the cake is due and have no way to get more. I live a mile away from a walmart so if something was to happen with the wilton fondant I could just make a quick run to the store to either get a package or pick up marshmallows to make my own.

I think if you bought a 5lb and a 2lb you should be fine. That gives you 2lbs back up. Or you could order two 5lbs. As long as they are wrapped well they store for a while.