About Project Estimate
Project Estimate turns the dimensions you measured into the quantities a supplier will actually sell you — with the formula, the assumptions and the rounding shown next to every number.
Who it is for
Homeowners and DIY builders working out what to order, and tradespeople and small contractors who want a quick take-off they can sanity-check. It is not a quantity surveying package and it does not try to be.
What it does differently
- It counts the way materials are actually laid. Decking is counted by row and gap, not by area. Paving is counted by module including the joint. Brickwork is derived from the co-ordinating size.
- It shows the rounding.Every quantity says where it came from: “27.40 boards, +10% waste = 30.14, rounded up to 31”.
- It handles compaction and settlement separately from waste. A 100 mm compacted sub-base needs about 130 mm of loose material. That is not waste, and treating it as such is why sub-base orders come up short.
- It publishes its data. All 28 densities, yields and allowances are on one page with their ranges, sources and review dates.
- It does not invent prices. Cost totals come only from prices you enter. No supplier prices are held, scraped or implied.
UK and US
There is one calculation engine, not two. What changes between regions is the configuration: units, currency, tax, terminology and the pack sizes suppliers sell. A UK user sees bulk bags, MOT Type 1, paving slabs and VAT; a US user sees cubic yards, gravel base, pavers and a sales-tax field they set themselves.
What is here now
6 complete calculators and 28 reference guides. Every calculator ships with full logic, both regions, unit conversion, waste handling, weight, a diagram, a shopping list, a methodology section and a test suite — or it does not ship. There are no placeholder calculators on this site.
Planned modules are listed openly on the calculators page rather than published as empty pages.
When it is wrong
It will sometimes be wrong. Densities vary by quarry, bag fill weights vary by merchant, and product sizes change. A calculation that disagrees with your supplier is a bug worth reporting, and reports are checked against the published sources rather than dismissed.
Report an error — it is the most useful thing you can do for the next person using the same calculator.
What it is not
It is not a structural design tool. It does not size joists, design foundations, specify reinforcement, assess ground conditions or confirm compliance with building regulations or local codes. Those are decisions for a qualified professional, and the calculators say so wherever they touch on them.