Room Area Calculator — Square Metres & Square Feet

How to Measure a Room Accurately

For accurate measurements, use a laser distance measurer or a long steel tape measure. Measure the length and width at floor level, as walls are not always perfectly square. In rooms with alcoves, chimney breasts or bay windows, break the space into rectangular sections, measure each one separately and add the areas together. For L-shaped rooms, divide the space into two rectangles, calculate each area and sum them.

Always measure in metres if you plan to buy materials priced per square metre, which is standard across UK suppliers. If your tape measure shows feet and inches, our calculator can convert the results for you. Note that room areas quoted on estate agent particulars may be measured differently, often including areas under fitted furniture, so always measure yourself for accuracy.

Using Room Area for Project Planning

Once you know your room area, you can use it to estimate quantities for virtually any home improvement task. Paint coverage is typically quoted in square metres per litre, flooring is sold per square metre or per pack covering a set area, and underfloor heating systems are specified by the square meterage they cover. Heating engineers use room volume, which is the floor area multiplied by the ceiling height, to calculate radiator sizes and heat loss.

Tradespeople also use room area to provide quotes. Plastering, decorating and flooring installation are commonly priced per square metre, so having an accurate measurement ready when requesting quotes helps you compare prices fairly and spot any estimates that seem unreasonably high or suspiciously low.

Common UK Room Sizes

A typical UK single bedroom measures around 7 to 8 square metres, a double bedroom 12 to 15 square metres, and a master bedroom 15 to 20 square metres. An average living room is 15 to 20 square metres, while kitchens range from 8 to 15 square metres depending on the property. Knowing these benchmarks helps you judge whether a room in a property listing is genuinely spacious or on the small side.

Try our paint calculator or flooring calculator once you have your room area. For guidance on building regulations and permitted development, visit GOV.UK.