About EstimatorKit

The calculators fall into 5 groups by the kind of job. The catalog on the homepage lists every calculator with a line on what it works out.

• Area & volume — 5 calculators
• Lumber & framing — 4 calculators
• Interior finishes — 4 calculators
• Yard & water — 4 calculators
• Charts & reference — 2 calculators

Every calculator here multiplies your measurements by somebody else’s number, and those numbers are not all the same kind of thing. The whole site keeps them in one table, compiled 2026-09-02, split into two classes that are labelled differently wherever they appear.

Fixed numbers are definitional or manufactured, and they do not vary. An acre is 43,560 square feet because that is what the word means. A 4 × 8 sheet of drywall is thirty-two square feet. An 80 lb bag of pre-mixed concrete yields 0.6 of a cubic foot, printed on the bag by every maker of it. Nothing about your site changes any of these, so they are stated as facts.

Moving numbers genuinely differ from load to load, and pretending otherwise is how an estimate goes wrong quietly. A cubic yard of topsoil is the worst of them: the topsoil page starts from 2,000 lb and uses 2,200 once it has been rained on, and neither figure is quoted from a published table, because topsoil has no specification to quote one from. A bag of blown-in insulation covers a different area from one brand to the next, which is why that page reads the chart printed on your own bag. Where a number moves, this site shows it as an editable default with a note on what shifts it, and says so when the default is a working figure rather than a published one — your supplier’s own figure should replace ours, because they weighed their pile and we did not.

Two adjustments sit between the geometry and the order and they pull opposite ways. Waste is material you buy and never place: offcuts, spillage, the tile that snaps. Compaction and settling are the reverse — material you place and then lose, because loose aggregate gives up depth under a plate compactor and screened topsoil settles once it is watered in. The site allows a fifth of the depth for the first and 15% for the second, and both are working allowances rather than measured ones.

Both are printed next to the bare figure wherever a page uses them, never blended into a single total. That is a deliberate constraint rather than a design preference: a padded number cannot be checked against a quote, and a calculator whose answer you cannot take apart is one you end up verifying somewhere else anyway.

Every cost figure on this site is one you typed. There is no built-in price per yard, no regional average, no “typical bathroom remodel in 2026”. A material price that is right in one metro is wrong two states away, and it is stale within a season anyway — publishing one would make the arithmetic look more authoritative while making the answer less true.

There is also no quote form and nothing here is passed to a supplier. Worth saying plainly, because a good share of the calculators ranking for these searches belong to someone who sells the material, which is a perfectly reasonable thing to publish and also a reason their default quantities tend to round in one direction.

1. Structural capacity. No page here sizes a joist, a header or a beam. The stair page reproduces the code’s dimensional limits with their section numbers and still leaves the verdict to the building official, because whether a part of your building is safe is a judgement your local code and a qualified engineer make, and a web page that issued it would be pretending to knowledge it cannot have.
2. Site conditions. A slab poured over soft or uneven ground takes more concrete than its dimensions say. A delivery that has to be barrowed round the back changes what is worth ordering. The geometry is exact; the ground is yours.
3. What your supplier will actually sell you. Minimum loads, short-load fees, pallet sizes and bag formats vary by yard. Where those matter — the bag-versus-bulk comparison especially — the page takes them as inputs rather than assuming a national norm.

Every calculation runs in the tab. Measurements, quantities and the prices your yard quoted you are multiplied in the browser and forgotten on reload — none of it is uploaded, logged or kept, which is also why these pages carry on working on a site with no signal once they have loaded.

This describes what EstimatorKit does. It says nothing about what a browser extension, a corporate proxy or the machine itself might see — only that this site adds nothing to that list.