How much paint do you need? Some handy tips

A coat of paint does more than add a splash of colour to your room; it can alter the sense of space and light. But figuring out how much paint you need can be a puzzle. Here's a handy tip sheet to help you get through the process.

• To estimate the amount of paint you'll need, first work out the total area of the surfaces that you'll be painting.
• If you're painting walls with windows in them, don't factor them into your calculations of total area — it's better to have too much paint than not enough.
• Check the can for how much of the paint is needed to coat one square metre (also known as its "coverage").
• Then crunch the numbers to find out how many cans of paint you'll need to cover your total surface area.
• Don't forget to multiply the results by the number of coats you think you'll need.

• Calculating surface area can be difficult when the room you want to paint has an irregular shape.
• First, measure the length of each section of wall, including the sides of any nooks.
• Add up those numbers and then multiply by the height of the walls in the room.
• Next, subtract the area of any doors.
• Now add the surface area of the ceiling.
• The figure you end up with is the total surface area for the room.
• Multiply that by the number of coats you think you will need.

• Most paint tins indicate the average area of wall they will cover.
• However, some surfaces will require a lot more than the advertised amount.
• Highly porous surfaces such as bare drywall or plaster, and rough surfaces such as un-stuccoed walls are very thirsty.
• Two or three undercoats may be necessary to cover a very strong base colour on such thirsty materials.

• For the best results, buy a premium paint product that a reliable paint retailer recommends.
• Cheaper products tend to have less "coverage" (so you'll need to buy more product anyway)
• In general, cheaper paints don't wear as well as a better paint either (so you'll be painting again, sooner if you choose them).
• Basically, if you spend more now, you'll save in the long run.

• Always buy more paint than you need; that way you'll avoid running short in the middle of the job and you'll have some left over for touch-ups.
• Buy paint in four litre (one gallon) cans rather than than one litre (one quart) tins.
• That way you'll get as much as two extra litres of paint for the same price.

With these handy tips in mind, your preparation for your next painting job is more likely to go as smoothly as a well-applied final coat.