An online construction calculator is only useful if it is the right one, and a contractor searching for one usually has a specific job in hand: a pour, a wall, a stair, a load of gravel. This page is the map of the calculators on this site, by job, with what each one needs typed in and what it produces, so the right one is one click away; it is also honest about what an online calculator cannot know, which is anything about your site, your crew and your prices that you do not type in. Every calculator here runs on the page from your own figures with no account; the construction cost estimator turns their outputs into a priced estimate.
Concrete, gravel and sand: the volume calculators
A pour is the concrete calculator: length, width and thickness in feet, divided by 27, plus waste, in cubic yards, with the pad and the price pages working a pad and its cost. A base or a drive is the aggregate calculator: area and depth into cubic yards and, at the supplier's density, tons. A bedding layer or a mix is the sand calculator, the same arithmetic with the ton conversion the other way. A wall is the block wall calculator: area into blocks with the mortar and grout. All four need the dimensions from the drawing and, for the ton conversions, the supplier's density; none of them knows the subgrade, which is what the waste line is for. NIST Handbook 44, linked below, is why the cubic yard on the ticket is the yard on the ground.
Framing, sheathing, drywall and stairs: the count calculators
A wall is the framing calculator, with the stud calculator working the count and the 2x6 calculator the deeper stock; the sheathing calculator turns wall and roof area into sheets; the drywall calculator turns wall and ceiling area into sheets, mud and tape; the stairs calculator turns a total rise into risers, treads and run, and the stair stringer calculator into a cut list; the board foot calculator prices lumber by the board foot. Each needs the dimensions and the spacing or sheet size, and each adds a stated waste. The wood handbook linked below is the reference behind the lumber sizes the count calculators assume.
Cost: the estimator that prices what the others count
The construction cost estimator takes the quantities the count and volume calculators produce, or a cost per square foot for a whole house, and prices them at the rates typed in, with site work, contingency and markup as visible lines, then prints the estimate as a CSV and a PDF. The contractor calculator page on this site is the four sums that feed it, and the material take off and labor calculator pages work the quantity and hours sides. It is the one calculator on this site whose output leaves the page as a document, and the one that asks the most of the person typing, because every rate is theirs.
What no online construction calculator can know
Your subgrade, your crew's pace, your supplier's price this week, the rock under the lot, the code your inspector enforces: an online calculator computes from what is typed in and nothing else, and every page on this site says so beside its result. That is the honest limit and the reason none of these calculators ships a built-in rate. The next step after any of them is a job record, where the estimate's lines, the purchase orders and the draws live together; DrawScheduleWorks Pro is that record, and the calculators here are the arithmetic it starts from.
Questions people ask about online construction calculator
Which online construction calculator do I need?
For a pour, the concrete calculator; for a base or drive, the aggregate calculator; for a wall, the framing or block wall calculator; for sheets, the sheathing or drywall calculator; for a stair, the stairs calculator; for the price, the construction cost estimator. Each is one page on this site.
Are the calculators on this site free?
Yes. Every one runs on the page from the figures typed in, with nothing stored and no account. The estimator's worked example downloads as a CSV and a PDF without an account either.
What can an online calculator not tell me?
Anything it is not told: the subgrade, the crew's pace, this week's prices, the rock under the lot, the inspector's reading of the code. Each page says so beside its result, and none ships a built-in rate.