Carpet installation contractors will provide measurements and estimates independent of your numbers, but it’s good to take your own measurements to ensure you’re getting a fair rate. Make a diagram for each floor of your home, marking the rooms and sections that you’ll need carpet for. Measure the length and width individually of each of these rooms, and take separate measurements for any interior closets or other spaces you want carpet installation in (so for a single bedroom with 2 closets, you should have 3 separate sets of widths and lengths). Repeat all of your measurements twice to avoid errors. Add up the total square footage of each room you need carpet installation in, and account for 5% extra material. You can always double check with your carpet installer to ensure you measured correctly.