Carpet Calculator

Carpet is measured by floor area and usually sold by the square yard: measure the room, multiply length by width and divide by 9 to get yards. Work out a room in square yards, square metres and square feet, plus the area including a waste allowance and the estimated cost from a price per square yard — with waste built in so you order enough.

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Carpet needed — square yards
Square metres — m²
Square feet — ft²
Area incl. waste — yd² to order
Estimated cost — at your price

How to Calculate Carpet

Measure the room, add waste, and read the square yards.

1

Choose how to enter the room

Use Room to type the length and width in feet or metres and let the calculator find the area, or switch to Area if you already know the floor area in square feet.

2

Enter the size and waste

Measure to the widest points of the room, including doorways you will carpet. Keep the waste allowance around ten percent, or raise it for stairs, patterns and rooms with many corners.

3

Read yards, metres and cost

You get square yards, square metres and square feet, the area including waste to actually order, and — with a price per square yard — the estimated cost.

Frequently Asked Questions

How do I measure a room for carpet?
Measure the longest length and the widest width of the room in feet and multiply them to get the floor area in square feet. For a plain rectangular room that is all you need. If the room is L-shaped or has a bay, break it into rectangles, work out each one and add them together, then enter the total in Area mode. Always measure to the widest points, including into doorways and alcoves that will be carpeted, because carpet is cut to the largest dimension of the room. It helps to sketch the room and note each measurement so you can double-check the figures before you order.
How do I convert square feet to square yards?
Divide the area in square feet by nine, because a square yard is three feet by three feet, which is nine square feet. So a room of 180 square feet is 180 divided by 9, or 20 square yards. Carpet in the United States is usually priced and sold by the square yard, so this conversion is the one you need before you can compare prices or place an order. The calculator does it for you and also shows the same area in square metres for anywhere that sells carpet by the metre.
How much extra carpet should I add for waste?
A waste allowance of about ten percent is a sensible default for most rooms, and that is the value the calculator starts with. Carpet comes on a fixed-width roll, so some is always trimmed off to fit the shape of the room, and larger or busier rooms need seams where two pieces are joined with the pile running the same way, which uses a little more. Go toward the higher end, twelve to fifteen percent, for rooms with lots of corners, a patterned carpet that has to be matched across seams, or stairs. The calculator adds your chosen percentage on top and shows both the bare area and the amount to actually buy.
Is carpet sold by the square yard or the square foot?
In the United States carpet is traditionally sold and priced by the square yard, although some retailers now quote a price per square foot, so it pays to check which one a quote uses before you compare. A price that looks low per square foot is nine times more per square yard, so the two are easy to confuse. The calculator gives you the area in square yards, square feet and square metres at once, so whichever way a shop quotes you can enter its unit price and read the cost. Enter your price per square yard in the price field to see the estimated total including the waste allowance.
What about carpet for stairs and hallways?
Stairs and hallways are the trickiest part of a carpet order because they are long, narrow and full of turns, so they waste more off the roll than an open room. For a straight flight, allow roughly the tread depth plus the riser height for each step and add them up, then treat that running length by the carpet width as its own area. Hallways are best measured as a simple rectangle at their widest point. Because both waste heavily, use a higher allowance of twelve to fifteen percent, or measure them separately and add the figures, rather than folding them into a single whole-house number.

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