All calculators
Every calculator here is built the same way: real geometry, an adjustable waste allowance, whole purchase units and visible working.
16 calculators
Measurement
Work out area, volume and perimeter for rooms, walls, yards and awkward shapes. Start here when you need a figure to feed into any other calculator.
Square Footage Calculator
Work out the area of a room, wall, yard or awkward shape in square feet or square metres. Add several sections, deduct openings, and carry the total into any material calculator.
Volume Calculator
Work out volume in cubic feet, cubic yards or cubic metres from length, width and depth. Add several sections and convert straight into the unit your supplier sells in.
Painting & Walls
How much paint a room needs once doors and windows are deducted, and how many sheets of drywall to board a wall. Coats, coverage and container sizes included.
Paint Calculator
How much paint a room needs with doors and windows deducted and coats accounted for. Enter the coverage from your own tin and get the number of cans to buy.
Drywall Calculator
How many sheets of drywall a room or wall needs. Deduct the openings, set your own sheet size, add a waste allowance, and get the whole sheets to order.
Flooring & Tile
Turn a floor area into whole boxes of laminate, vinyl or tile, with a waste allowance for cuts and a grout joint that changes how far each tile really goes.
Flooring Calculator
Turn a room area into whole boxes of laminate, vinyl or wood. Enter the coverage printed on your box, add a waste allowance for cuts, and see exactly what is left over.
Tile Calculator
How many tiles and how many boxes a floor or wall needs, with the grout joint added to both dimensions so each tile really covers slightly more than its nominal size.
Concrete & Masonry
Volume for slabs, footings, columns and post holes, then the choice that follows it: how many bags to mix yourself, or how much ready-mix to order.
Concrete Calculator
Volume of concrete for a slab, footing, column or post hole, in cubic yards or cubic metres, with an overage allowance and the ready-mix quantity to order.
Concrete Bag Calculator
How many bags of concrete mix a pour needs. Enter the yield printed on your bag, measure the slab, footing or posts, and get whole bags with an overage allowance.
Landscaping & Garden
Depth-based materials for outdoor work: gravel, mulch and topsoil by the cubic yard, cubic metre or bag, plus pavers for a patio or path. Density and coverage explained.
Gravel Calculator
How much gravel a driveway, path or bed needs at your chosen depth, in cubic yards, cubic metres or bags, with an optional density so you can order by weight.
Mulch Calculator
How much mulch a bed needs at your chosen depth, in cubic yards, cubic metres or bags. Rounds up to whole bags and shows what that order actually covers.
Soil Calculator
How much topsoil a bed, lawn or raised planter needs by depth, in cubic yards, cubic metres or bags, with whole-bag rounding and an optional weight to order by.
Paver Calculator
How many pavers a patio, path or driveway needs, worked out from the size of the paver you have chosen, with a waste allowance for the cuts around the edges.
Fencing & Decking
Posts, panels, pickets and deck boards along a run. The post count is sections plus one, which is the mistake most estimates make and the one these tools avoid.
Fence Calculator
Posts, panels, pickets and rails for a fence run. Counts posts as sections plus one, shares a post at each corner, and takes gate openings out of the fenced length.
Decking Calculator
How many deck boards a deck needs, from board width and length with the gap between them added to the width only, plus a waste allowance for the cuts.
Roofing & Exterior
Roof pitch as a ratio, angle and slope factor, and the roof area that follows from it. Convert a footprint into real sloped area and into roofing squares.
Roof Pitch Calculator
Convert a roof pitch between rise per 12, percentage, angle in degrees and slope factor, then use that factor to turn a flat footprint into real roof area.
Roofing Calculator
Roof area and roofing squares from a footprint and pitch, or from a sloped area you measured directly, with a waste allowance and whole bundles to buy.