Know exactly how much material to buy — before you drive to the store.
Six focused calculators for the jobs that always end in a second trip: concrete, paint, mulch, tile, gravel and sod. Every result shows bags, cubic yards, gallons or tons, so you can order with confidence.
Pick your project
Each calculator uses the same formulas contractors use on an estimate — with the bag yields, coverage rates and densities printed on the product label.
Concrete Calculator
Cubic yards, plus 40, 60 and 80 lb bags for slabs, footings and post holes.
Bags & cubic yardsPaint Calculator
Wall and ceiling area, minus doors and windows, across one to three coats.
GallonsMulch Calculator
Bed volume in cubic yards and 1.5, 2 or 3 cu ft bags at any depth.
Cubic yards & bagsTile Calculator
Square footage with waste allowance, boxes to order and tile count.
Boxes & tilesGravel Calculator
Driveways, paths and drainage beds by volume, weight and tons.
Tons & cubic yardsSod Calculator
Lawn square footage converted to rolls and pallets before delivery.
Rolls & palletsPrefer everything on one screen? See all six calculators on a single page →
Why these numbers can be trusted
Most “how much do I need” answers online are a single paragraph with no math shown. Every page here documents the formula, the constants and a worked example you can check by hand.
Published constants
Bag yields from manufacturer specs (an 80 lb bag of concrete mix yields 0.60 cu ft), paint coverage of 350 sq ft per gallon, and 1.4 tons per cubic yard of gravel.
The math is on the page
Each calculator shows its formula and a fully worked example, so you can sanity-check the result against your own tape measure.
Runs in your browser
Nothing you type is uploaded or stored. The calculator is a few kilobytes of JavaScript, so it loads instantly and works offline once cached.
Learn the numbers first
Short, practical guides for the questions that come up before you order materials.
How much concrete do I need?
Bag yields per cubic yard, slab thickness rules of thumb, and when ready-mix beats bags.
GuidePaint coverage per gallon
What 350–400 sq ft really means once you factor in texture, colour changes and primer.
GuideHow deep should mulch be?
Two to four inches, and why going deeper can damage the plants you are trying to protect.
GuideBuilt for people mid-project
You are standing in an aisle with a phone in one hand and a cart in the other. A calculator that asks for twelve fields and hides the answer behind a “calculate” button is useless in that moment. Each tool here has sensible defaults, updates as you type, and puts the number you actually need — bags, gallons, tons — first.
If a result looks wrong, the formula is printed underneath it. Check the constants against the label on the bag and adjust for the one thing no calculator can see: how uneven your sub-base is.
Questions, corrections or a calculator you want added? Tell us — the list of next tools is driven entirely by those messages.