Craft Quantities
Plan & Takeoffs

Solve backwards

I have this much — what will it do?

Almost every calculator here runs one direction: you know the job, you want the quantity. On site the question is usually the other way round, with a pallet already in the yard — I have this, what will it do? Each page answers it with the calculator that would have ordered it.
  • 82Materials, read backwards
  • 80Calculators behind them

Find what you have

Search by material

All 82 materials, by how they are sold.

17 materials

Paint, primer, stain and sealer

Tins and pails, read as the wall, floor, deck or drive they finish at the coats the job needs.

9 materials

Sheets and boards

A stack of sheets, read as the wall, floor or roof it lines — with the cut waste taken back out.

14 materials

Rolls

Membranes, wraps and underlays, read as the area they cover once the laps are taken off.

22 materials

Bags and bulk

Bags, cubic yards and cubic metres, read as the bed, slab or base they fill at a depth.

18 materials

Counted pieces

Bricks, blocks, pavers, boards and tiles, read as the wall, patio or floor they build.

2 materials

Water and capacity

A tank, a barrel or a supply, read as what it holds, fills or serves.

Start from what you have

Tins, sheets, rolls, bags or pieces: enter the amount, and the page grows its calculator's own starting job until the quantity it asks for is exactly that — then says the area and the size of room, deck or drive it makes.

Why the waste allowance flips

Ordering forwards, you add a percentage for cuts and breakage, because some of what arrives never ends up in the work. Reading backwards from a stack you already own, the same percentage has to come off. Dividing straight through without that step is how a job ends one sheet short on the last wall.

The calculator's own figures

Nothing is estimated twice. Each page runs the calculator you would order with, at its own settings, and lists them beside the answer — so the answer moves exactly as that calculator does when you change one.

10 calculators

Calculators that already read backwards

These take what you have as an input rather than a page reading them the other way — the stock count, the circuit, the roof.

I already have the material

I have a count, I want the measure

What will this system carry?

The other direction

Know the job, not the stock?

The takeoffs start from a room or a named job and work out everything it needs to buy.

Job takeoffsEvery calculator

  • One calculator, both ways

    The page that says how far your paint goes runs the calculator that would order it.

  • The largest size that fits

    Where a calculator rounds up to whole containers, the answer stops before the next one.

  • Both unit systems

    Gallons and litres, square feet and square metres, side by side.

Frequently asked questions

What does solving backwards mean?
Starting from what you already have instead of from the job. Every calculator here runs forwards — a size in, a quantity out — and each page runs one of them the other way: it grows the calculator's own starting job until the quantity it asks for is what you have, and reports that size.
Why does my stack cover less than its face value?
Because wherever a calculator adds an allowance for cuts, breakage or laps when you order, the same allowance comes back off when you work out how far a stack goes. Twenty sheets do not finish twenty sheets' worth of wall; they finish that less the offcuts, and each page says which allowance its calculator carries.
Are the figures in gallons or litres?
Both. Each page answers in the unit system you have chosen and gives the other beside it, so a US gallon and a litre, a square foot and a square metre, sit side by side. The amounts in each page's table are the sizes the material is commonly sold in for that system.
Can I change the assumptions?
Yes. Every page lists the settings its calculator used — coats, spread rate, depth, waste — and links to that calculator with the size it found already entered, so you can change any of them and see the quantity move.