Estimate carpet area from total built-up area, or reverse the estimate, using a fixed 70% ratio in sq ft, sq m, or sq yd. Select the quantity to solve for and enter the known area. Actual usable floor area depends on the building layout; this ratio is not a measurement or legal area certification.

Fixed 70% estimate; actual usable floor area depends on the building layout.

Watch the full explainer with transcript and worked examples.

Carpet Area Formula

The following two example problems outline the steps and information needed to calculate the Carpet Area.

CA = BA × .70
  • Where CA is the Carpet Area (ft^2)
  • BA is the total built-up area (ft^2) 

To estimate carpet area with this tool’s fixed assumption, multiply built-up area by .70. To reverse the estimate, divide carpet area by .70. Both areas must use the same units before applying the ratio.

How to Calculate Carpet Area?

The following example problems outline how to calculate Carpet Area.

Example Problem #1:

  1. First, determine the total built up area (ft^2).
    • The total built up area (ft^2) is given as: 1000.
  2. Finally, calculate the Carpet Area using the equation above: 

CA = BA * .70

The values provided above are inserted into the equation below and computed.

CA = 1000 * .70 = 700 (ft^2)

Example Problem #2: 

For this problem, the variables required are provided below:

total built up area (ft^2) = 2000

Test your knowledge using the equation and check your answer with the calculator. The estimated carpet area is 1400 ft².

CA = BA * .70 = ?