How do I calculate the square footage of a room before I order flooring?

Measure the length and the width in feet and multiply them. The FloorBox guide How to Install Carpet states that method. If the room is not one rectangle, measure it in sections and add the sections.

How do I convert square feet to square yards for broadloom?

That same guide states that one square yard equals 9 square feet, and that you divide the square feet by 9. Broadloom product pages list both Coverage (sqft) and Coverage (sqyd). Start with Broadloom Carpets.

Where do I see how much area a FloorBox product covers?

On the product page, under the specifications, read Coverage (sqft). Shop the rolls in Broadloom Carpets or the modules in Carpet Tiles.

How much extra carpet should I order after I have the square footage?

The FloorBox carpet install guide says to order 10 to 20 percent more than the measured area, for mistakes and for cutting along the walls. It also says to add 6 inches along the longest wall when you cut the carpet. That guidance is for carpet installation on that page, not a rate published for every flooring type. Carpet and the pad under it are in Carpet and Carpet Underlayment.

What do I measure if I am buying carpet tiles instead of a roll?

Calculate the room the same way, length times width, then compare that number with Coverage (sqft) on the tile product page. Carpet Tiles is the FloorBox category.

Does the square footage change when the room has a closet or a jog?

Yes. Measure the closet or the jog as its own rectangle and add it to the main area. The carpet install guide says to measure a non-rectangular room in sections and add them. Then match the total to the coverage on the product you choose in Carpet.