Area units are squared
A square metre is an area, not a length. Converting metres to feet and then forgetting to square the factor is a common source of error.
Useful relationships
1 m² is approximately 10.7639 ft² and 1.196 yd². One acre is approximately 4,046.856 m².
Convert before applying coverage
If product coverage is stated in m², convert the measured area to m² before dividing by the coverage rate.
Keep one working unit
For UK material estimating, using metres and square metres throughout the calculation usually reduces unit mistakes.
Use the numbers in a calculator
Accuracy note
Where a figure depends on a product, supplier, installation method or project specification, use the current information for the exact material being purchased. The reference pages explain the maths and estimating logic; they are not a substitute for current technical data.