Home Carpet Replacement Cost Calculator

You need five numbers. Measure the room first, then enter the prices from your quote.

1. Measure the room length and width in feet and multiply them to get the area in square feet. Include closets you want carpeted.
2. Enter the room area in square feet.
3. Enter the carpet price, the padding price and the installation price, all in dollars per square foot.
4. Enter the waste percentage. Use 10% for a plain rectangular room.
5. Press Calculate, or press Enter. The total cost appears first and large, with the carpet needed, the carpet cost and the cost per square foot below.

The total is the sum of three lines, and only the carpet line includes waste. Carpet comes on 12 ft wide rolls, so cutting and seams always use more carpet than the floor area. Padding and installation are charged on the room area, not on the extra carpet that is cut away.

Carpet needed = room area x (1 + waste%), rounded up to a whole square foot. Carpet cost = carpet needed x carpet price per sq ft. Padding cost = room area x padding price per sq ft. Installation cost = room area x installation price per sq ft. Total cost = carpet cost + padding cost + installation cost. Cost per sq ft = total cost / room area. In this formula the room area is the floor area you measured, and the waste percentage is the extra carpet allowed for cutting, seams and pattern matching. Our carpet calculator can help you work out the area and the square yards first if your quote is written per square yard, since one square yard equals 9 square feet.

A homeowner replaces the carpet in a 300 sq ft room. The carpet costs $3.50 per sq ft, the padding costs $0.75 per sq ft, the installation costs $1.50 per sq ft, and the waste allowance is 10%.

1. Carpet needed: 300 x (1 + 10%) = 300 x 1.10 = 330 sq ft.
2. Carpet cost: 330 x $3.50 = $1,155.
3. Padding cost: 300 x $0.75 = $225.
4. Installation cost: 300 x $1.50 = $450.
5. Total cost: $1,155 + $225 + $450 = $1,830.
6. Cost per sq ft: $1,830 / 300 = $6.10.

As a second check, take a 144 sq ft bedroom at $3.00 carpet, $0.50 padding, $1.00 installation and 10% waste. The carpet needed is 159 sq ft, because 144 x 1.10 is 158.4 and it rounds up. The carpet cost is $477, the padding is $72, the installation is $144, the total is $693 and the cost per sq ft is $4.81. The same steps work for any room, so try your own numbers in the tool above.

The carpet price moves the total the most, because it is charged on the waste adjusted area and it varies the widest. Common carpet runs $1.50 to $7 per sq ft, so the same 300 sq ft room can cost very different amounts with a budget carpet and a premium one. Padding usually runs $0.30 to $1.50 per sq ft, and installation usually runs $0.50 to $2 per sq ft, so both matter less than the carpet itself but still add hundreds of dollars on a large room.

Waste is the number people forget. At 10% waste the worked example needs 330 sq ft of carpet, and at 15% it needs 345 sq ft, which adds $52.50 to the carpet cost at $3.50 per sq ft. Room size changes the total in a straight line when the prices stay the same. At the worked example prices a 100 sq ft room costs $610, a 300 sq ft room costs $1,830 and a 500 sq ft room costs $3,050, and each one works out to $6.10 per sq ft. Our flooring calculator helps you compare the same room priced in a hard floor if you are weighing carpet against another material.

In the worked example the carpet is about 63% of the total, the installation is about 25% and the padding is about 12%. The carpet is $1,155 of the $1,830 total, the installation is $450 and the padding is $225. That split is typical for a mid range job, and it tells you where to look when a quote seems high. If the carpet line is far above the rest, the grade is doing the work. If the installation line is far above $2 per sq ft, ask what extra work it covers.

Padding is the smallest line, but it decides how the carpet feels and how long it lasts. A cheap thin pad can make a good carpet feel flat within a year, while a denser pad protects the carpet from foot traffic. Do not save money by reusing the old pad, because a compressed pad can void the carpet warranty. Paint the room before the new carpet goes in, and our paint calculator works out how many gallons you need.

Measure every part of the floor that will be carpeted, including closets and doorways, and split an odd shaped room into plain rectangles and add them together. Ask the installer how the carpet will be laid, because a room wider than 12 ft needs a seam or a filler strip from the 12 ft roll, and the seam should sit under furniture or across the room rather than down the middle of a walkway.

Get 2 to 3 written quotes on the same carpet, the same padding and the same area, and check that each one lists carpet, padding and installation as separate lines. Ask whether the quote includes removing the old carpet, because removal usually adds $0.50 to $2 per sq ft and this calculator does not include it. Replace the padding with the carpet. If other rooms need work too, our kitchen remodel cost calculator prices a bigger project the same way, from area and finish level.