About CostZora
CostZora exists for one reason: most homeowners start a project with no idea what it should cost, and the first quote they receive is impossible to judge.
What we do
We maintain a set of free calculators that convert measurements into quantities and quantities into a realistic price range. Every calculator states its assumptions, so you can disagree with a number instead of guessing.
How the numbers are checked
Quantities are tested against supplier coverage charts and manufacturer installation guides. Prices are compared with published retail and trade pricing each season, and updated when the difference is large enough to change a result by more than a few percent.
When a range is unusually wide, that is deliberate: it reflects genuine regional spread rather than uncertainty in the arithmetic.
How the site is funded
Every calculator on this site returns a planning estimate, not a quotation. Prices are built from national averages and published supplier rates, then rounded. Material quantities are computed with standard industry allowances (waste factor, coverage per unit) and should be confirmed by your contractor before ordering. This site is free to use and funded by advertising. Advertisers have no influence on the estimates, the method pages, or the calculators that appear first.
What we do not do
- We do not sell leads or pass your details to contractors without asking.
- We do not quote a single price and imply it is guaranteed.
- We do not accept payment to rank a calculator or a material first.
Who writes this
CostZora is written and maintained in-house by a small editorial team that works on residential estimating. The calculators, the cost ranges and the guides are produced by the same people, so a figure quoted in a guide always matches the maths behind the calculator it links to.
We are not a contractor marketplace, and the site is not a lead-generation funnel with a calculator attached. Where a number is genuinely uncertain — regional labour rates are the usual culprit — we widen the range and say so rather than implying a precision we do not have.
Where to go next
- All 27 cost calculators — material quantities and cost ranges for outdoor and renovation projects.
- Cost guides — 25 in-depth articles on what a project should cost and why.
- Construction cost by state — 12 state profiles showing how local rates move a national average.
- Methodology — how quantities and prices are derived from supplier charts and published pricing.
Contact
Questions, corrections or a price you think is wrong? Write to us through our contact form.
Last reviewed: . Cost ranges are re-checked each season and the pages that change are re-dated.