Material estimators

Measure once

Every estimator here runs on the same rooms. Measure on the square footage calculator, press the button for the material you are buying, and the rooms come with you — shapes, cutouts, units and all. Doors and windows entered on one estimator are known to the others.

Nothing is uploaded to do it. The measurements travel inside the link, after the #, which browsers never send to a server.

What each one does differently

• Flooring adds the waste your laying pattern really costs — a herringbone throws away more plank than a straight lay — and then rounds up to whole boxes, because that is the unit a shop sells.
• Tile works out the narrowest grout joint the tile standards allow for the tile you are laying, counts tiles in the space they really take up with the joint included, and works out the grout as a volume from the gaps rather than from a guessed constant.
• Carpet cuts each room in drops off a fixed-width roll, lays it whichever way buys less, and counts the seams — because carpet comes in roll widths, not square feet, and the offcut is often a third of what you pay for.
• Baseboard plans the cuts wall by wall instead of dividing, which is the difference between three lengths and four on a room whose walls do not fit the stock length.
• Paint takes the doors and windows off the walls, multiplies by the coats, and packs the result into gallons and quarts, or into the tin sizes your shop stocks.
• Wallpaper cuts every wall into drops rounded to the pattern and counts how many one roll really gives — which is why a patterned paper can need half as many rolls again as wall area divided by roll area says. Pick a single wall and it works out a feature wall.
• Drywall counts sheets the way the manufacturers do, figuring doors and windows solid, and adds the joint tape, compound and screws the board needs to be finished.

The wall pages share one ceiling height, so a room measured for paint is already measured for wallpaper and drywall.

Outside

The garden calculators take the same measurements another way: the calculator’s total goes across as one bed, a path or a drive, and the question becomes how deep.

• Mulch offers the depths two extension services give — 2 inches for fine material, 3 for wood and bark, 4 for coarse nuggets — and says so when a bed is asked to go deeper than they advise.
• Gravel weighs the stone at a road handbook’s figure, or at your supplier’s, and knows that a compacted base is ordered a third deeper than it finishes.
• Topsoil weighs soil at the figure soil scientists use for a silt loam, gives the lawn and raised-bed depths the extension services do, and shares a bed out between topsoil and compost.
• Sod has no depth: it is the lawn and a little over, in the pads, rolls and pallets growers sell, with what the order weighs.
• Cubic yards add up a job of many parts — a patio, a path, a round bed — each at its own depth, with rooms from the calculator arriving one section each.
• Pavers count the pavers in the space each takes with its joint, and the base, the sand and the dig under them.

Each of them sells loose or in bags, in cubic yards or cubic metres, and a metric page counts the bags a British shop sells: litres of bark and soil, kilograms of stone.

Building

• Concrete adds up slabs, footings, post holes and steps, pour by pour, with the allowance the ready-mix industry advises, and counts bags at the yields their makers print.
• A deck is counted row by row — whole boards where a row fits in one, joined over a joist where it does not — with the joists and the screws, for a US composite deck or a British softwood one, and its footings go to the concrete page.
• A roof is measured from the ground: the footprint, the overhang and the pitch give its area, its squares and bundles, and the edges the ridge cap, starter and drip edge run along.
• Siding is measured the way its maker estimates: vinyl counts the windows and doors in and half of a garage door out, fiber cement takes every opening off. Then the cartons or planks, the trim in the lengths it is sold in, and the house wrap.
• Insulation starts from ENERGY STAR’s level for your climate zone and counts the bags a maker’s chart needs for it — with the depth to blow it to, because the chart’s R-value needs both — for an attic, for walls filled from outside, or batts under a floor.

The numbers behind them

Every default on these pages — coverage, waste, stock lengths, box sizes, roll widths, joint widths — is a published figure with the page it came from and the date it was read, listed at the bottom of each calculator. Where the sources disagree, and on waste they often do, the page says so rather than picking one and looking confident; where a figure is this site’s own choice rather than a published one, the page says that too.