Rectangle Area Calculator

How to find a rectangle’s area

1. Enter the length and width, choosing each measurement’s unit. Feet and inches has separate fields: enter 12 feet and 8 inches rather than 12.8 feet.
2. Choose a result unit, such as square metres or square feet. This converts the area without changing your measurements.
3. Read the area, open Calculation details for the method, or copy the summary. No extra material allowance is included.

Length, width and square units

Area is length multiplied by width after converting both dimensions to compatible units. A square follows the same rule with equal sides. Length and width are interchangeable.

One foot is 0.3048 metres and one inch is 0.0254 metres. Square-unit factors are squared: 1 ft² is 0.09290304 m² and 144 in² is 1 ft². Feet are not square feet.

Input unit selectors describe the numbers you entered; they do not convert them. Use 8.5 inches for eight and a half inches. Changing the result unit does convert the calculated area.

Rectangle-area examples

A 4 m by 3 m rectangle has an area of 12 m². Dimensions of 400 cm by 300 cm describe the same rectangle.

A rectangle 20 ft long and 12 ft wide has an area of 240 ft², or 22.2967296 m² before display rounding.

12 ft 8 in by 10 ft 6 in gives 133 ft². The sides are 152 inches and 126 inches: multiply them, then divide by 144.

Area is not a material order

This page measures one rectangle or square, not irregular outlines, surveyed property or official building areas. Split an L-shaped space into nonoverlapping rectangles and add their areas.

The result adds no allowance for cuts, damage or installation and does not count packs, tiles or paint. Use the Flooring Pack Calculator for product coverage and your chosen allowance.

Your measurements

The arithmetic runs in your browser. This calculator adds no input upload, saved project or measurement-bearing URL. The surrounding website still uses its normal consent, analytics and network services.