How to calculate paint for an Australian room
The formula is: paintable area ÷ coverage rate × number of coats = litres needed. For a full room, paintable area is wall area + ceiling area, minus doors and windows. This calculator does all of that automatically.
How much does a litre of paint cover?
Most Australian paints cover 12–16 m² per litre per coat. Budget and trade paints typically sit at 12 m²/L. Mid-range paints (Dulux Wash&Wear, Taubmans, British Paints) are around 14 m²/L. Premium high-hide formulas can reach 16 m²/L. Always check the coverage rate on the tin — it varies significantly between products.
How many coats do I need?
- 1 coat — touch-up or same colour refresh over a sound surface
- 2 coats — standard for most repaints and new plasterboard
- 3 coats — dark colours, going light over dark, or heavily patched walls
New plasterboard always needs a sealer coat first — factor this in separately at 10–12 m²/L.
Walls vs ceiling — do I use the same paint?
Generally no. Ceiling paint is flat/matte to hide imperfections and reduce glare. Wall paint is usually low-sheen or semi-gloss for washability. Budget them separately — most painters apply ceiling white first, then cut in and roll the walls.
What tin sizes are available in Australia?
Standard sizes are 1 L, 2 L, 4 L, 10 L and 15 L. The 10 L tin is the best value for rooms over ~25 m² of paintable area. For small rooms or feature walls, 4 L is usually sufficient. Always buy slightly more than calculated — leftover paint is useful for touch-ups.