Carpet Calculator

By HomeAdvisor

Updated January 20, 2021



Area 1 (in ft.)
Area 2 (in ft.)
Area 3 (in ft.)
Area 4 (in ft.)
*Includes standard 10% waste.

To use the calculator:

  1. Enter the length and width of each room.
    1. Don’t forget to measure for doorways.
    2. Divide irregularly shaped rooms into smaller square sections.
  2. Enter the number and width of your stairs.
  3. Add 10% to 20% to your final figure for waste.

Carpet Cost Calculator: Installation and materials average $700-$2,600 depending on the type, regional pricing differences and how much furniture needs moving. Get multiple quotes and find a carpet installer near you today.

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How to Measure for Carpet

To measure for a carpet, measure each area individually following the steps listed below. Figuring carpet area means multiplying width times length for each area and adding them together. You’ll follow slightly different methods for rooms and stairs.

How to Measure a Room or Hallway for Carpeting Installation

Area = Length x Width.

simple room measurement

  1. Measure the length using the distance from one wall to the opposite wall.
  2. Measure the width from wall to wall.
  3. Add 2 to 4 inches to each side. This accounts for waste, doors and slanting walls. It’s easy to cut a little off for a perfect fit, but it’s impossible to add without creating unsightly seams.
  4. Multiply the length times the width or enter those into the calculator above. This is your total square footage for that room.
  5. Repeat this process for each room.
Not Sure How Much Carpeting You Need?

How to Measure Stairs for Carpet

Width x ((Run+Rise+Nose) x Number of stairs) = Area

measuring stairs for carpet or flooring

For a straight staircase:

  1. Measure the rise and run. Add them together. Include an inch or two extra to wrap around the nose.
    • Rise: height of the step.
    • Run: length of the step.
  2. Multiply that by the number of stairs.
  3. Divide by 12 and round up to get the number of feet.
  4. Measure the width of the stairs and round up to the nearest foot.
  5. Multiply the width from step 4 by the length from step 3.
  6. Add in any landings you have. Multiply the width and length of the landing. Add that number.

If you have an irregular, circular or unique setup, it’s best to hire a professional.

For a stairwell with 13 stairs and one landing:

  1. 7+7+2 = 16 inches. 7 inches for each rise and run plus two inches for the nose and overage
  2. 16 inches x 13 stairs = 208 inches.
  3. 208 inches/12 = 17.33 (round up) = 18 feet.
  4. 4 x 18 = 72 square feet. Width is 4 feet.
  5. 4 x 4 = 16 square feet for the 4-foot by 4-foot landing.
  6. 72+16 = 88 total square feet.

How to Figure Carpet Waste

Total area + 10%-20%

When you measure for carpet, expect at least 10% waste. If you have a unique layout, up that to 20%.

With so few width options, you’ll likely end up with plenty of waste. However, if you simply cut up the rolled carpet to minimize waste, you’d end up with a disaster of patchwork seams. You’ll have higher waste with carpet than other types of flooring due to the standard roll sizes.

For a whole house with two 10’x10’ bedrooms and a 9’x15’ living room:

  • To Cover: 335 square feet
  • Carpeting To Purchase:
    • Bedrooms: Two 12’x10’ pieces. One for each
    • Living Room: One 12’x15’ piece.

Total Needed: 420 square feet (21% waste).

Need Help Measuring Carpeting?

How Carpet is Sold

Retailers sell carpet in precut widths on a roll, most commonly 12 feet in width. 13.5- and 15-feet widths are also available. If you have a room 10 feet wide by 10 feet long, you’ll need to purchase a 12 foot by 10-foot section of the roll.

A couple of notes to consider before purchasing:

  • Be skeptical of carpet ratings. Often, they’re rated by the manufacturer for marketing purposes, not for any standardized ratings in the industry.
  • Hide the seams in doorways. Because of the standard roll sizes, measure your home room by room to the midpoint of doorways. This leaves all seams hidden under doors.
  • Carpet remnants. These common roll widths means you’ll purchase more carpet than you actually need, typically about 10% to 20% more. These extra pieces are called remnants. Use them in out-of-the-way spots like closets.
  • Get it from a professional installer. When you hire a carpet professional, they’ll only charge you for actual square feet installed. They usually account for a small amount of overage and waste, usually 10%.

Carpet Square Foot vs. Square Yard Calculator

Width x Length = Area

Total Square Feet / 9 = Square Yards

graph of complex L-shaped room measurement

To calculate the square footage of carpet you’ll need, multiply the length times the width, in feet, of any space where you’ll install flooring. It also helps to sketch out a diagram of your home’s layout. It doesn’t need to look good, but make sure the measurements are accurate.

Most retailers now sell by the square foot. However, some professionals still use the older method of square yards. To find the square yard, simply divide your square foot number by nine.

Carpet Tile Sizes

Carpet tiles often come in 12-inch by 12-inch (12”x12”) or 24-inch by 24-inch (24”x24”) squares. If you want to minimize waste, consider using carpet tiles. Typically sold for high traffic commercial spaces, it both minimizes waste and makes it easy to replace small sections.

Carpet Estimator by Type

The type of you choose, like the popular Berber carpet, has no impact on how you’ll measure your floor, only your budget and design.

Choosing the right type of carpet for your home does mean varying costs and design choices. As part of your flooring research, look into the various types in our carpet buying guide. Then calculate carpet costs by type.

Rug Calculator

Calculating the size of the rug you need depends entirely on the aesthetics of the room. Typically, you’ll want one to cover high traffic areas. For best results, leave a few feet around the edge of the rug to the wall. If you’re unsure what size you need, hire an interior decorator.


What is a standard carpet roll width and length?

Carpet rolls come in standard widths of 12 and 15 feet. Less commonly, you might find a roll 13.5 feet wide. There are no standard roll lengths, but they’ll have enough to cover almost any home.

How much carpet and padding do I need?

You’ll need equal amounts of carpet padding and carpet. Carpet padding costs $200 to $500 for the average room. However, the padding is trimmed a couple inches away from the wall on all sides to make room for tack strips. Most residential installs have padding, and professionals include this in their bids.

Often, the best carpet for basements doesn’t include a pad. You’ll find this mainly in humid areas or places with a high-water table.

What is a linear foot of carpet?

One linear foot of carpet or other material is simply one foot measured in a straight line. You typically aren’t going to measure carpet this way. It’s quoted in square feet or square yards.

How many square feet in a yard of carpet?

There are nine square feet in one square yard of carpet.

How much carpet is needed to cover 2 rooms?

The amount of carpet you need to cover two rooms varies depending on the room size and configuration. Measure the floor space. Multiply width times length. Do this for both rooms and add the numbers together.

How much carpeting for 13 stairs?

You’ll need between 80 and 110 square feet for 13 stairs. For unique stairwells, you might need more.

How do I find indoor/outdoor carpet measurements?

Measure indoor/outdoor carpet like you would any other area, taking the width times the length. For patios, make sure to add a couple extra inches to wrap around the edges. Indoor-outdoor carpets cost an average of $3.50 per square foot.

How much carpet do I need to repair a tear or pet damage?

You’ll need enough carpet to cover the entire area of damage to avoid seams. For example, if you have a 4-inch tear in the middle of a hallway, you’ll want enough carpet to stretch from door to door or the next available seam. Depending on the type of carpet you have, you might be able to get a professional to do an invisible seam repair.

How big is a square foot of carpet?

One square foot of carpet is one foot long by one foot wide.

Find Pros to Install Your Carpeting


  1. Cathy Maddox, January 17:

    Could you explain how you got the answer in yards.

  2. Jason, January 21:

    If I have 5728 square yarded room how much carpet would I need

  3. HomeAdvsior, January 24:

    Hi Cathy,
    I square foot is equivalent to about 0.11111 square yards. The tool estimates this measurement for you.

  4. Diana, December 13:

    So I would need 37 yards for to 12×14 rooms?

  5. jerry, December 18:

    Multiply the length times the width and divide that total by 9. Round the number after the decimal UP to the next higher number. Example 24.3333 would round up to 25.
    Another example: room is 16′ long and 20′ wide, multiply 16 times 20 which equals 320. Now divide 320 by 9. Your answer should be 35.55. Now round up to 36 and you have how many sq.yds. you need.

  6. Joann, May 6:

    If I want to recarpet 12 steps using a carpet runner. The carpet runners are 28 inches wide. How much carpet so I need?

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