Flooring & Tiles

Carpet Quantity Calculator

Estimate carpet area and linear roll length with practical fitting waste.

Flooring & tile estimate

Enter the measured surface and product size for Carpet Quantity Calculator

Method for this tool

What the Carpet Quantity Calculator actually calculates

The engine increases floor area by the fitting allowance and divides by roll width. This preserves area only; it does not arrange cuts, maintain pile direction, match patterns, or ensure that the roll covers the room width. Stairs, alcoves, and seamed rooms need a measured cutting plan.

The calculation path

Adjusted floor area is divided by the chosen carpet-roll width to give linear metres.

Inputs that can change the answer

Room length: Enter room length in m.
Room width: Enter room width in m.
Roll width: Enter roll width in m.
Fitting allowance: Percentage applied at the stage shown in the method; enter 10 for ten percent.

Checks that stay outside the formula

A fitter should confirm seam placement for rooms wider than the roll.

A practical order for entering the data

Enter the rectangular room length and width in metres.
Choose the actual carpet roll width and a fitting allowance percentage.
Use the approximate roll length for early budgeting and have the seam and pile-direction layout checked before ordering.

Engine check using the prefilled sample

Flooring example: room length = 5 m, room width = 4 m, roll width = 4 m and fitting allowance = 10 %. Replace the sample dimensions and pack information with the measured floor and the exact product format you intend to order.

Results for these inputs

Floor area: 20.00 m²
Order area: 22.00 m²
Approximate roll length: 5.50 linear m

Project-specific method

Worked example and purchase checks

This calculator gives an area-based estimate using room dimensions and the fitting allowance, then compares that quantity with the entered roll width. It is a planning aid, not a cutting plan.

Illustrative worked example

A room slightly wider than a 4 m carpet roll, where area alone cannot confirm the correct linear order.

Exact inputs for this example

Room length	4.9 m
Room width	4.15 m
Roll width	4 m
Fitting allowance	8 %

Floor area: 20.34 m²
Order area: 21.96 m²
Approximate roll length: 5.49 linear m

How to read the result

Use the result to compare material scale and cost, then draw the cut rectangles against the actual roll width before ordering.

Assumptions this example makes

The room is rectangular and one roll width is being considered.
The fitting allowance is an area allowance, not a seam or pattern layout.

What this calculator does not prove

Sheet flooring and carpet orders depend on roll direction, seams, pattern matching, and usable offcuts.
An area-equivalent linear length can understate the real order when the room is wider than the roll.

Room versus roll-width checkSketch is explanatory, not to scale.

Mistakes that change this result

Buying from square metres alone without checking roll width.
Ignoring pattern direction or seam location.
Assuming a leftover strip from one cut can always be reused elsewhere.