How to calculate Square foot?

Measure the length and width in feet by tape

Use Formula to calculate sq. foot Length x width = Sq. foot

Suppose,  you measured 12 feet length and 10 width

Insert the value into formula (length x width) 12 x 10 =120

The answer 120 is total square foot

If you wish to measure in inches then use this second method.

After measuring in inches use this formula  (length x width = sq. ft./144) 

if you measured 132 and 126 inches  then add it as 132 x 126 = 16632

16632 is total square inches divide it by 144

After dividing by 144 the answer will come out and that's sq. foot.

132 x 126 = 16632 16632/144 = 115.5 is sq. foot