All calculators

35 calculators, grouped by the part of the job they belong to. For the parts a number cannot answer — base depths, cure times, what the box actually tells you — there are the guides.

Concrete & Masonry

Brick calculator — How many bricks and bags of mortar for a wall. Worked from your brick size and joint thickness, because 6.75 per sq ft is only true for modular brick.
Concrete block calculator — How many concrete blocks and bags of mortar for a wall. Coverage is worked out from the real 15-5/8 in block plus your joint width, not a rule of thumb.
Concrete driveway calculator — Cubic yards, bags and control joints for a concrete driveway. Joint spacing and saw depth come from ACI 302.1R, not from a rule of thumb.
Concrete footing calculator — Cubic yards, bags and rebar for strip footings, pads and round deck piers. The rebar count adds the code lap splice at every joint, not just the run.
Concrete calculator for post holes — How many bags of concrete per fence post, with the post itself subtracted from the hole. Works for 4x4, 6x6 and metal posts, general or fast-setting mix.
Concrete sealer calculator — How much concrete sealer you need, from published data-sheet coverage. Texture and porosity are asked separately, because the sheets say both decide the rate.
Concrete slab calculator — Work out the cubic yards, bags of concrete mix and total weight for a slab. Enter length, width and thickness, and see whether bagged mix or ready-mix is cheaper.
Concrete stairs calculator — Concrete for stairs and steps, worked as a stack of steps rather than a box. Treating a flight as one box of the total rise by the total run counts the air above every step, and doubles the concrete exactly.
Mortar calculator — How many bags of mortar for block or brick — and which bag. Preblended mortar mix lays 13 blocks; masonry cement plus sand lays 46. Both are published.
Rebar calculator — How much rebar for a slab or footing grid: bar counts, code lap splices, sticks to buy and the weight. Counts two short bars out of one 20 ft stick.

Landscaping

Artificial turf calculator — How much turf and infill for a lawn. Infill rates are published product measurements in pounds per square foot, so this asks for the rate rather than deriving one from the pile height.
Grass seed calculator — How much grass seed you need, at the rate published for your grass type. Bermuda takes 2 lb per 1,000 sq ft and tall fescue 8 — one rate ruins lawns.
Gravel calculator — Work out tons and cubic yards of gravel for a driveway, shed base or path. Asks which stone you are buying and whether it gets compacted, because both change the tonnage.
Mulch calculator — Work out cubic yards and bags of mulch from your bed area and depth. Includes the coverage per cubic yard at the depth you choose, which is the figure to check a bulk delivery against.
Paver sand calculator — Work out bags of bedding sand and polymeric joint sand for a paver patio. Uses the ICPI 1 in bedding depth and coverage by joint width, not a flat figure.
Paver calculator — How many pavers you need, plus the crushed stone base under them — including the compaction allowance and the excavation that has to run wider than the patio.
Retaining wall block calculator — How many retaining wall blocks, caps and cubic yards of drainage gravel you need — including the buried bottom course, which is easy to leave out of a height-times-length sum.
Sod calculator — Work out pallets, slabs or rolls of sod from your lawn area, plus what the load will weigh. Pallet coverage runs 400 to 600 sq ft by region, so this asks for yours instead of guessing.
Topsoil calculator — Work out cubic yards and bags of topsoil for a raised bed, lawn or garden. Uses the 0.75 cu ft bag stores actually stock, and allows for settling.

Interior

Carpet calculator — How much carpet a room needs once roll width is accounted for. Turning the room 90° can change the order by half, and this shows both ways round.
Drywall calculator — Sheets of drywall for a room, plus the joint compound, paper tape and screws to finish it. Uses the manufacturer coverage tables, not the 0.05 gal/sq ft myth.
Floor tile calculator — How many floor tiles you need, rounded up to whole boxes, with the waste factor set by your layout and the thin-set bags to go with it. Diagonal and herringbone cost more.
Grout calculator — How many pounds and bags of grout you need, from tile size, joint width and tile thickness. Joint depth equals tile thickness, so a 1/2 in paver takes twice the grout of a 1/4 in wall tile.
Laminate flooring calculator — How many boxes of laminate flooring to buy, not just the square footage. Box coverage varies from 16 to 30 sq ft by style, so the count is never the same twice.
Paint calculator — How many gallons of paint a room needs. Deducts the doors and windows, and prices the first coat separately because bare drywall drinks it.
Wallpaper calculator — How many rolls of wallpaper you need, counted in strips and adjusted for the pattern repeat. A 25 in repeat on an 8 ft wall throws away a fifth of every roll.

Exterior

Deck board calculator — How many deck boards you need, in the lengths you can actually buy. Uses the real 5.5 in board width and your board gap, and counts the deck screws too.
Deck stain calculator — How many gallons of deck stain you need, counting the railing, stairs and fascia — not just the floor. Rough or weathered wood drinks nearly twice as much.
Drip edge calculator — How many 10 ft pieces of drip edge for the eaves and the rakes, with the 2 in code overlap taken off. Linear feet is only the first of the three numbers you need at the counter.
Fence picket calculator — How many fence pickets, posts and rails you need for a run of fence. Uses real dressed lumber widths — a 1x6 is 5.5 in, not 6 in — so the count is right.
Gutter calculator — Gutter sections, hangers, and how many downspouts the run actually needs — sized from the roof area draining into it and your local rainfall intensity.
Metal roofing panel calculator — How many metal roofing panels you need, and the exact length to order. Built on net coverage width — not the width on the price tag, which leaves you short.
Roof shingle calculator — Bundles of shingles for your roof, corrected for pitch. Also gives the starter strip and the hip and ridge cap, priced from each product’s own linear coverage, so you buy once.
Roofing underlayment calculator — How many rolls of felt or synthetic underlayment your roof needs. #15 covers four squares a roll, #30 covers two, synthetic ten — and the lap eats all three.
Vinyl siding calculator — Squares and boxes of vinyl siding, plus the J-channel, corner posts and starter strip that go with them. The trim is half the order, so this counts it too.