How do I measure a room for carpet?

Measure the length and the width of the room at their widest points and multiply them for the floor area. Add a waste allowance because carpet comes in fixed width rolls and needs trimming, and seams have to line up. The calculator adds the allowance for you.

Why is there waste with carpet?

Carpet is made in set roll widths, usually 3.66 metres, so cutting a room to fit almost always leaves offcuts. Hallways, stairs, and pattern matching add more. A 10% allowance is a sensible starting point, but your installer will measure exactly.

Does the price include underlay and fitting?

This calculator costs the carpet only, from the price per square metre you enter. Underlay, smoothedge, delivery, and installation are usually extra, so ask for a full quote that includes them.

Carpet Calculator

Estimate the carpet you need for a room and what it will cost. Enter the room length and width, a waste allowance, and the price per square metre. The calculator shows the floor area, the area to order including waste, and the carpet cost. Underlay and fitting are usually extra.

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Room length (m)

Room width (m)

Waste

Price per m²

estimated carpet cost

Floor area0 m²

Order (with waste)0 m²

Carpet only. Underlay, smoothedge, delivery, and fitting are usually extra.

How it works

The floor area is the length times the width. Because carpet comes in fixed width rolls and needs trimming and seam matching, a waste allowance is added, often around 10%. The cost is the area to order times the price per square metre.

Worked example

A 4.5 by 3.6 metre room is 16.2 square metres. With 10% waste you order about 17.8 square metres. At $75 a square metre, the carpet is about $1,336, before underlay and fitting.

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