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How much do you need?

Calculators for concrete, paint, tile, flooring, roofing and more — with the formula, waste factor and a shopping list for every estimate.

Popular calculators

Concrete Slab Calculator Estimate cubic yards, cubic metres and bags of concrete for a slab, patio or pad — with waste factor, the formula and a shopping list.
Paint Calculator Work out gallons or litres of paint for a room, with doors, windows, coats, ceiling and primer — plus the tin sizes to buy.
Deck Board Calculator Work out how many deck boards, joists, screws or hidden clips you need for a deck, using real board widths, gaps and stock lengths.
Flooring Calculator Calculate boxes of laminate, vinyl plank or hardwood flooring for any room, with layout waste, underlay and baseboard length.
Fence Calculator Estimate fence posts, rails, pickets or panels and post-hole concrete for any fence length, with gates and real post sizes.
Mulch Calculator How much mulch do you need? Get cubic yards, cubic metres and the number of 2 or 3 cu ft (50/70 L) bags for any bed and depth.

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Why trust our numbers?

Method shown

Every page shows the formula, the default values we use and where they come from. Open “Show the math” to see each step.

Our methodology

Sources cited

Defaults such as bag yields, coverage rates and densities come from manufacturer data and industry bodies — and you can override them.

Editorial policy

Tested engine

Each calculator has golden test cases checked by hand. Purchase quantities always round up to whole bags, boxes and sheets.

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