Paint tray with orange paint and paint tin in background on drop sheet

It is important to work out exactly how much paint you require for your job as it is costly if you end up with too little or too much paint. If you buy less paint than required you will end up having to purchase 1L tins which is more expensive than buying 10-15L tins. If you purchase too much paint you then have the costly disposal expense of the left over paint. There is a simple equation to help you save money and purchase the correct amount of paint and here it is:

  1. Measure the perimeter of the room. Measure lengths and widths and add all four numbers together (or more than four if the room is not a simple rectangle)
  2. Multiply the perimeter by the height of the room
  3. Deduct windows and doors. An average window is approximately 1.5m2 and an average door is approximately 2m2
  4. Divide by 14 (one litre of paint covers about 14m2 when applied at the correct spread rate)
    • Legth + Length + Width + Width = Total perimeter (m)
    • Total perimeter x height – (doors + windows) = Total area (m2)
    • Total area (m2) / 14 = Number of Litres needed per coat
    • NOTE: If two coats are required double the number of litres

Handy Tips

  • Always round up to ensure that you will have enough paint to complete the job
  • Add paint for other interior areas such as trim, ceilings and doors