Carpet Calculator
Square yards of carpet and padding for a room, with waste.
10% plain carpet, 15% for patterns or complex rooms, 20% with stairs.
You need
22.0 sq yd
Waste included. Rooms wider than the 12 ft roll need seams; confirm layout with the installer.
- Padding needed
- 22.0 sq yd
- Floor area
- 180 sq ft
- Area with waste
- 198 sq ft
Estimates only. Verify quantities before ordering.
How this is calculated
Square yards = length x width x (1 + waste) / 9, since one square yard is 9 square feet. Padding matches the carpet area. Broadloom rolls are 12 ft wide, so rooms wider than 12 ft involve seams that can add usage beyond this estimate.
Enter the room dimensions and this calculator converts them into square yards, the unit carpet is priced in, for both carpet and the padding underneath. The waste factor covers seam trimming, squaring the ends, and pattern matching; 10% suits a plain carpet in a simple room, 15% is safer for patterned carpet or rooms with jogs and closets.
Broadloom carpet comes on 12 ft wide rolls (some styles 13 ft 6 in or 15 ft), and that roll width, not just area, decides your real usage. A 13 ft wide room needs a seam and can consume noticeably more than the raw area suggests, while a 12 ft wide room fits a roll perfectly. For rooms wider than the roll, have the installer plan the seam layout before you order.
Carpet for common room sizes
Rows include 10% waste. Padding quantity matches the carpet figure.
| Room size | Carpet | Area |
|---|---|---|
| 10 x 10 ft | 12.2 sq yd | 100 sq ft |
| 12 x 10 ft (bedroom) | 14.7 sq yd | 120 sq ft |
| 12 x 12 ft | 17.6 sq yd | 144 sq ft |
| 15 x 12 ft (living room) | 22.0 sq yd | 180 sq ft |
| 20 x 15 ft (great room) | 36.7 sq yd | 300 sq ft |
Common questions
How many square feet in a square yard of carpet?
Nine. Divide square feet by 9 to get square yards. A 12 x 15 room is 180 square feet, or 20 square yards before waste. Some retailers now price by the square foot instead; the math converts either way.
How much extra carpet should I order?
10% beyond the measured area for plain carpet in a simple room, 15% for patterned carpet (repeats must match at seams) or rooms with closets and jogs, and about 20% when carpeting stairs, which eat roughly 2.5 square feet per step on a standard staircase.
Do I need new padding?
Almost always, yes. Padding compresses to the old carpet's traffic patterns, and worn pad makes new carpet feel dead and wear faster. Most carpet warranties require new pad of a specified density, typically 6 to 8 lb rebond for residential use.
How do seams affect how much carpet I need?
Carpet must run the same direction on both sides of a seam, so a room wider than the 12 ft roll needs a second piece cut from the roll's length, often leaving a large unusable strip. That is why installers measure and plan a seam diagram; for wide rooms, expect real usage above the simple area math.