Calculators
Building calculators
Building jobs live and die on quantities: boards in lineal metres, stair rises that must comply with the NCC, tiles by the box and paint by the litre. These calculators handle the conversions and the compliance checks so you can order materials and check quotes with confidence.
Each one shows its working, uses Australian standards where they apply and prices materials at typical July 2026 rates.
Building material prices in Australia
Decking, stairs and structural timber
Decking boards cost $5 to $9 per lineal metre for treated pine, $10 to $16 for merbau and $12 to $22 for composite as at July 2026. A typical 20 square metre deck needs 220 to 250 lineal metres of 86mm boards once waste is counted, so material choice alone swings the board bill from about $1,200 to over $5,000.
For stairs, the material is a small part of the cost but compliance is everything: risers, goings and the 2R+G comfort rule all have NCC limits that inspectors check. The stair calculator flags them live as you type.
Tiling and painting
Ceramic floor tiles start around $25 per square metre and porcelain runs $40 to $120, with adhesive and grout adding $8 to $12 per square metre in materials. Professional laying costs $50 to $90 per square metre. On top of tiles themselves, allow 10 percent waste for straight lays and 15 percent for diagonal.
Interior paint costs $12 to $55 per litre depending on tier, and a litre covers about 16 square metres per coat. A standard bedroom needs 4 to 5 litres for two coats of the walls. Quality matters most in wet areas and high traffic zones where washability earns its premium.
Roofing measurements
Roof pitch drives material choice: corrugated steel needs at least 5 degrees while concealed fix profiles go nearly flat, and tiles want 15 degrees or more. The roof pitch calculator converts between degrees, ratios and percentages, and gives rafter lengths for framing and ordering.
Typical Australian prices, updated July 2026.
Frequently asked questions
What are the NCC rules for stairs?
For private stairs: riser height 115mm to 190mm, going 240mm to 355mm, and twice the riser plus the going must land between 550mm and 700mm. Every riser in a flight must be equal.
How many decking boards per square metre?
About 11.1 lineal metres of 86mm boards or 7.1 lineal metres of 136mm boards per square metre, plus 10 percent waste. The decking calculator counts rows, screws and joists for your exact deck.
How much does tiling cost in Australia?
Tiles range from $25 to $120 per square metre, materials like adhesive and grout add about $10, and professional laying runs $50 to $90 per square metre as at July 2026.
What roof pitch do I need for metal sheeting?
Corrugated profiles generally need 5 degrees minimum. Trimdek style profiles go to 2 degrees and concealed fix systems as low as 1 degree. Always check the manufacturer specs for your profile.
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