Construction calculators for concrete, gravel, asphalt and more. Punch in your dimensions and get bags, tons, cubic yards and cost in seconds. Order the right amount the first time, because nobody has ever enjoyed a second trip to the supply yard.
Accurate estimates for every job, from a humble backyard slab to a genuinely ambitious parking lot.
Volume, 60/80 lb bags and ready-mix truck loads for slabs, footings and pours.
Open calculator →Area for rooms, floors and walls - rectangle, triangle or circle.
Open calculator →Cubic yards, tonnage and total cost for driveways and landscaping.
Open calculator →Convert any length, width and depth into cubic yards, feet and tons.
Open calculator →Hot-mix tonnage and paving cost for driveways and parking lots.
Open calculator →Cubic yards and 2-cu-ft bags needed for any bed depth.
Open calculator →Sheets, screws and joint compound for walls and ceilings.
Open calculator →Roof area, roofing squares and shingle bundles from footprint and pitch.
Open calculator →Paintable wall area and gallons of paint for any room, coats included.
Open calculator →Every calculator uses the same formulas the pros use, standard material densities, bag yields and waste factors. Order the right amount the first time, dodge the second delivery, and protect your margin like it owes you money.
Free for contractors, builders and weekend warriors alike. No account, no email, no limits.
Nothing on this site guesses. The volume tools multiply length by width by depth, convert everything to feet, and divide by 27, because a cubic yard is 27 cubic feet and suppliers sell by the yard.
Bag counts come from the yields printed on the bag rather than a rule of thumb. An 80 lb bag of concrete mix yields 0.60 cubic feet and a 60 lb bag yields 0.45, per the Quikrete Concrete Mix data sheet, which is why a full yard takes 45 of the big bags or 60 of the small ones. Run the concrete calculator at its default 10 by 10 foot slab, 4 inches thick with 10 percent waste, and you get 1.36 cubic yards, 62 eighty-pound bags, or 82 sixty-pound bags. The waste factor defaults to 10 percent because no subgrade is ever as flat as the sketch says it is.
Weight conversions use standard planning densities: crushed stone and gravel at 1.4 tons per cubic yard, dry sand at 1.35, hot-mix asphalt at 145 pounds per cubic foot, which is why a compacted yard of asphalt weighs close to 2 tons. Cost figures are simply your quantity times the unit price you type in. The one page that quotes a real price, the 2026 slab cost tables, uses a retail bag price checked at Home Depot and Lowe's and dated on the page. Wherever a constant comes from a manufacturer sheet, an extension bulletin, or a code section, that source is named on the page that uses it.
ConcreteCalcTools is owned and run by Chris Terry through Encore Promotional Products. He builds the calculators and signs off on every constant before it ships. Jessica Martinez writes the cost and material guides that back the tools up. What each of them checks, and against which sources, is spelled out on the authors page and the editorial standards page. Wrong numbers reported through the contact form get fixed and dated, not quietly swapped.
The cards above cover the big nine. These handle the rest of the job list:
Every example above is the calculator's own default scenario, so you can open any tool and see the same numbers before touching an input. The guides section carries the longer answers: cure times, slab thickness by use, what a driveway costs installed, and how to pour a slab without learning each lesson the expensive way.
Bag yields, aggregate density and code minimums come from a Quikrete or Sakrete data sheet, a university extension office, or the International Residential Code, cited by name on the editorial standards page, not a rounded number nobody can trace.
Guides like how much concrete you need and estimating footings show the arithmetic by hand, length times width times depth divided by 27, so you can check the calculator's answer yourself instead of trusting a black box.
The 2026 slab cost tables download as a CSV with cubic yards, bag counts and material cost for ten common slab sizes, built to bring to the supply yard rather than re-typed from a screenshot.