# Liner Calculations

QuoteSoft calculates liner from the inside of the duct item. Then scrap is applied. Below is an example of a 12x12 duct that is 1 foot long with 1 inch liner applied.

The liner panels that go inside the duct item will have to be cut to fit inside the duct and inside the liner itself. We’ll use this example to walk through the calculations.

**2 sections of liner at 12in width and 12in length**

12x12 = 144 square inches for one panel

144 x 2 = 288 total square inches

288 / 144 = 2 square feet

**2 sections of liner at 10in width and 12in length**

10x12 = 120 square inches for one panel

144 x 2 = 240 total square inches

288 / 144 = 1.667 square feet

Total square feet of liner = 3.667

After QuoteSoft calculates the total square feet, the scrap percentage is then applied.