Paint calculator
To work out how much paint is needed for your interior or exterior project use our paint calculator!
Instructions:
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If you know the surface area enter it in the "Surface area" box below, then enter in the Spreading rate and Number of coats and click on "Calculate".
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To calculate the surface area Learn more about calculating surface area enter the Height and Length of the area to be painted, click "Calculate Surface Area" and then enter in the Spreading rate and Number of coats and click on "Calculate".
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To find the spreading rate go to the product data sheets and labelsFind the spreading rate... page, click on the name of the product you plan to use, and then click on the the data sheet # or label. The data sheets list the spreading rate as "Theoretical coverage" and the labels list this as "Coverage". Both the data sheets and labels will also tell you how many coats you require.
(Surface area ÷ Spreading rate) x Number of coats = the litres of paint required
| Height(m): |
| Length(m): |
NB: Porous surfaces and shapes (ie corrugated iron) will require more paint.
Roof painting tip
A good rule-of-thumb for calculating the quantity of roof paint required is: your project's footprint area plus about 40% (allows for roof pitch, corrugations, soffit overhang, etc). Trough section roofing can require significantly more. Typically a complete roof paint system requires surface preparation using Resene Roof and Metal Wash, one coat of primer and two coats of topcoat at the recommended coverage rate on the cans.
Further information on estimating paint –
Learn how paint amounts are estimated...
To determine how much paint you need for your project you will need the following information:
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Surface area of the surface(s) to be painted (excluding areas where there are windows, doors etc).
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Spreading rate of the paint being used.
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The number of coats needed.
For example:
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To paint the living room walls excluding the ceiling. The walls are 3 metres high, each wall is approx 4 metres in width, and windows and doors make up approx 0.5 of a metre of each wall leaving a paintable surface of 3.5 metres per wall. The surface area to paint is therefore 14 metres (4 walls x 3.5 metres each) x 3 metres high = 42 square metres.
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The walls are currently painted and are in good condition. Resene SpaceCote Low Sheen is the selected paint system. The product label and data sheet tells us that it has a theoretical spreading rate of 11 square metres per litre. (You can view product data sheets and labels to get the spreading rate info for the product you plan to use.)
- As the walls are previously painted and in good condition, only two coats of Resene SpaceCote Low Sheen are required.
The amount of paint required is therefore:
Surface area: 42 square metres
Divided by
Spreading rate: 11 square metres per litre
Multiplied by
Number of coats: 2 coats
Equals
42/11 x 2 = 7.6 litres
This tells us that 7.6 litres of paint is required to paint two coats onto the living room walls. The best idea would then be to purchase 8 litres giving enough paint to complete the job and sufficient to go back if touch up is required later.
To make calculating your paint requirements even easier, use the calculator above.
Disclaimer: This quick estimate works as a general guide for most houses, but extreme designs or colour palettes tailored to each room will need a more careful approach with each room calculated individually.