Depending on what you're estimating, you can input either the material cost or the consumer cost. For example, if you charge consumers $7 per square foot and sell a 4" by 14" decal at $2.72, the price would be $2.72. If you estimate your material cost at $50 for 400 square feet, then your estimated cost is $10,000. The consumer cost is easy to calculate - it's just the cost of materials times the number of square feet you need to purchase. So if your material cost is $50 and your area is 400 square feet, then your estimated cost is $20,000. The material cost is more difficult to estimate. The first thing you should do is look up the material cost of a similar product. Then use that as a starting point and adjust according to how much vinyl you need to buy. For example, if you need 100 yards but only have access to 50 right now, then you should use half of the starting point (in this case, 25 dollars). After you know the material cost, you can calculate the estimated cost per square foot. Divide the total amount by the number of square feet you need to purchase to get your estimated cost. In our example, this would give us $12.50 as our estimated cost per square foot.