Skip to content
ToolLantern

Flooring Calculator

Work out the square footage (or m²) of flooring to buy, how many boxes that is, and what it will cost.

Quick answer

Flooring needed = room area plus 5–10% waste (more for diagonal or herringbone layouts), rounded up to whole boxes. Tiling instead? Use the tile calculator.

  • Free
  • No sign-up
  • Home
  • Updated October 2026
ft
ft
%

5–7% for simple rooms, 10–15% for many corners or diagonal installs.

sq ft

Printed on the box, e.g. 20 sq ft.

Flooring to buy

198 sq ft

Room area
180 sq ft
Show the working
  1. 15 × 12 = 180 sq ft
  2. + 10% waste = 198 sq ft

About the Flooring calculator

Flooring is sold by the box, and each box covers a set area printed on the label. The calculator adds your waste allowance, rounds up to whole boxes and prices the boxes you’ll actually buy — not just the room area.

Measure each room at its widest point and include closets and doorways that will be floored. Leave the material in the room for 48 hours before fitting; most laminate and wood manufacturers require it.

How to use it

  1. Enter the room length and width.
  2. Set waste: 5–7% for simple rectangular rooms, 10% for most rooms, 15% for diagonal installs.
  3. Add the coverage per box from the packaging.
  4. Add the price per square foot or m² to estimate cost.

The formula

Flooring = Length × Width × (1 + Waste %)

  • Boxes = Flooring ÷ Coverage per box, rounded up.
  • Cost = Boxes × Coverage per box × Price per unit area.

Worked example

A 15 × 12 ft living room

  1. Area: 180 sq ft.
  2. With 10% waste: 198 sq ft.
  3. At 20 sq ft per box: 9.9 → 10 boxes (200 sq ft).

Frequently asked questions

How much extra flooring should I buy?

Around 10% for most rooms. Simple rectangles with straight boards can manage 5–7%; herringbone and diagonal layouts need 15% or more.

Should I include closets?

Yes, if they will get the same floor. Measure them separately and add the areas together.

Do I need underlayment?

Most floating laminate and many vinyl floors need underlayment unless it is pre-attached. It is sold by area, so the same square footage applies (without the waste factor).

Results are estimates for planning — check critical figures with a professional or the official source.

Popular tools

Image Converter

Convert any image to JPG, PNG or WebP, with quality and size controls.

Image

JPG to PNG Converter

Turn JPG files into PNG right in your browser — drag in one image or thirty.

Image

PNG to JPG Converter

Turn PNG files into JPG right in your browser — drag in one image or thirty.

Image

WebP to JPG Converter

Turn WebP files into JPG right in your browser — drag in one image or thirty.

Image