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Carpet Calculator

Work out how much carpet a room or several rooms need, the roll length required, and the total cost of carpet, underlay, and fitting.

Units

Rooms

Room 1

Waste and roll width

Around 10% covers a straight layout with a couple of seams; use more for an irregular room or a pattern that needs matching.

Pricing

Calculated in your browser as you type. Nothing is uploaded.

Total cost
469.33
for 132 sq ft (14.67 sq yd, 12.26 sq m) including 10% waste
366.67
Carpet
58.67
Underlay
44.00
Fitting
120 sq ft
Total room area (13.33 sq yd, 11.15 sq m)
11 ft
Roll length needed (12 ft wide roll)
1
Rooms

This is an estimate. The real amount needed shifts with the room’s shape, seam placement, and any pattern matching, so round up rather than down when buying.

How to calculate carpet for a room

  1. Choose your units and enter the room size

    Pick feet and inches or metres, then enter the length and width. Add more rooms and they are totalled together.

  2. Set a waste allowance and roll width

    Add a waste percentage for seams and off-cuts, and enter the roll width you plan to buy from.

  3. Enter the price per area

    Choose square feet, square yards, or square metres, then enter the carpet price and, if needed, underlay and fitting cost per area.

  4. Read the total cost

    The result updates instantly with the total area, the area including waste, the roll length needed, and the total cost broken down by carpet, underlay, and fitting.

Why use this tool

Multiple rooms, one total

Add as many rooms as the job needs and their areas, waste, and cost are combined into a single total automatically.

Feet and inches or metres

Enter room dimensions in feet and inches or in metres, and switch between them without losing the values already entered.

Every area unit at once

Every area figure is shown in square feet, square yards, and square metres together, whichever unit the carpet is priced in.

Roll length at a chosen width

Enter the width of the roll you plan to buy from and see the length needed to cover the total area including waste.

Underlay and fitting included

Optional underlay and fitting costs per area are added to the carpet cost for one combined total, or left blank to price carpet alone.

Private by design

Every measurement and price you enter is calculated in your browser. Nothing is uploaded or stored.

About this tool

This tool works out how much carpet a room, or several rooms together, will need and what the job will cost. Enter each room’s length and width in feet and inches or in metres, and the areas are added into one running total. A waste allowance accounts for the trimming and pattern matching every real installation involves, and the total is reported in square feet, square yards, and square metres at once so it matches however your supplier prices carpet.

Enter the width of the roll you plan to buy from and the tool works out the length needed to cover the total area, including waste. Add a carpet price per area, and optionally an underlay and a fitting cost per the same area, and the total cost is broken down by each of the three so it is clear what is being paid for. Every field recalculates instantly as you type or switch units, and rooms can be added or removed freely.

Like any estimate, the real amount needed shifts with the room’s shape, where seams fall, and whether a pattern needs matching across the width, so it is worth rounding up rather than down when buying. Everything runs in your browser, so the measurements and prices you enter are never uploaded or stored. For tiling a floor with individual tiles instead of a single sheet of carpet, use the tile calculator.

Frequently asked questions

How is the total area calculated?
Each room’s length is multiplied by its width to get an area, and the areas of every room entered are added together. The total is then converted so it can be read in square feet, square yards, and square metres at the same time.
How much waste allowance should I use?
Around 10% suits a simple rectangular room with a couple of seams. Irregular room shapes, a lot of doorways or alcoves, or a carpet pattern that needs matching across a seam usually call for 15 to 20% or more.
What does roll length needed mean?
Carpet is bought as a length cut from a roll of a fixed width. Once the roll width is entered, the tool divides the total area, including waste, by that width to work out how much length off the roll is needed to cover it.
Are underlay and fitting required fields?
No. Leave them at zero if you only want the cost of the carpet itself. When filled in, they are priced per the same area unit as the carpet and added to give one combined total.
Are the measurements and prices I enter kept private?
Yes. The whole calculation runs in your browser. Every room dimension, price, and cost you enter is never uploaded, stored, or logged.

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