Carpet Calculator
Find out how much carpet to buy and what it will cost to install. Add up to three rooms and this carpet calculator gives you the floor area in square feet and square yards, the roll length to order with seams and trim included, padding and an installed cost range.
Your results will appear here.
How to use the carpet calculator
- Measure each room at its longest and widest points, including any closets you want carpeted. You can type feet and inches.
- Enter up to three rooms. Leave the length and width of unused rooms at 0.
- Choose the roll width. Most carpet in the US is sold in 12 ft wide rolls. Some styles come in 13 ft 6 in or 15 ft.
- Pick the carpet quality and padding to see an installed cost range.
- Tick removal if your old carpet needs to come up first.
How carpet is calculated
Carpet is sold by the square yard but cut from long rolls, so you usually buy more than the floor area. The calculator:
- Works out the floor area: Length × Width ÷ 9 gives square yards.
- Lays the roll in both directions in each room and picks the layout that uses less carpet.
- Adds 3 in to each cut for trimming at the walls.
- Multiplies the roll length you need by the roll width to get the carpet to buy.
Square yards = Square feet ÷ 9
Carpet to buy = Strips needed × (Room length + 3 in) × Roll width
Worked example
A 15 x 12 ft bedroom with a 12 ft wide roll:
- Floor area: 15 × 12 = 180 sq ft, or 20 sq yd
- The 12 ft width fits the room in one strip, so you need 15 ft 3 in of roll
- Carpet to buy: 15.25 × 12 = 183 sq ft, or about 20.3 sq yd
If the same room were 15 x 13 ft, the 12 ft roll would no longer cover it in one strip, and you would need a seam and much more carpet. That is why roll width matters.
Carpet installation cost (2026)
The calculator adds these price ranges per square foot. Carpet is priced on the amount you buy, and padding, labor and removal are priced on the floor area. Carpet, standard pad, labor and removal prices are based on HomeGuide’s carpet cost guides, and the premium pad range on Inch Calculator’s 2026 carpet cost guide. The three carpet grades are HomeQuantly groupings within HomeGuide’s material price ranges.
| Item | Cost per sq ft | Cost per sq yd |
|---|---|---|
| Budget carpet (polyester) | $1.00 – $2.50 | $9 – $22.50 |
| Mid-range carpet (nylon, triexta) | $2.50 – $5.00 | $22.50 – $45 |
| Premium carpet (wool, high-end) | $5.00 – $10.00 | $45 – $90 |
| Standard padding | $0.25 – $1.00 | $2.25 – $9 |
| Premium padding | $1.00 – $2.00 | $9 – $18 |
| Installation labor | $0.50 – $1.50 | $4.50 – $13.50 |
| Old carpet and pad removal | $0.70 – $1.60 | $6.30 – $14.40 |
For the 15 x 12 ft bedroom above with mid-range carpet, standard padding and removal, the calculator estimates about $719 to $1,653 installed.
Tips before you order carpet
- Let the installer measure. Use this calculator to budget, then have the store or installer measure before you order, since they plan seams and pile direction.
- Keep pile direction the same. All pieces in a room should run the same way, or the color will look different from piece to piece.
- Do not skimp on padding. A good pad makes carpet feel softer and helps it last longer.
- Ask about extra charges. Stairs, moving furniture, floor repairs and transitions to other flooring are often priced separately.
Frequently asked questions
How do I calculate square yards of carpet?
Multiply the room length by the width in feet to get square feet, then divide by 9. A 12 x 15 ft room is 180 sq ft, or 20 sq yd. Because carpet comes in fixed roll widths, you may need to buy a little more than that.
How much carpet do I need for a 12 x 12 room?
A 12 x 12 ft room is 144 sq ft, or 16 sq yd. With a 12 ft roll and 3 in for trimming, you would buy a 12 ft 3 in piece, about 16.3 sq yd.
How much does it cost to carpet a 12 x 12 room?
With mid-range carpet, standard padding, installation and removal of the old carpet, this calculator estimates about $576 to $1,325 for a 12 x 12 ft room in 2026. Budget carpet costs less and premium carpet costs more.
Why do I need more carpet than my room size?
Carpet is cut from rolls that are usually 12 ft wide. If your room is wider than the roll, you need a second strip and a seam, and every cut needs a few extra inches for trimming at the walls.
What is the most common carpet roll width?
In the US, 12 ft is by far the most common width. Some carpets are also made in 13 ft 6 in and 15 ft widths, which can help avoid seams in wider rooms.
Sources and methodology
Planning estimate only. Prices are 2026 national averages compiled by the HomeQuantly Team from the published sources below and last reviewed on November 9, 2026. Your local prices may be higher or lower. Always get written quotes from licensed local contractors.