Free building material calculators for real projects.
BuildCalc turns project dimensions into square feet, cubic yards, tons, bags, boxes, and optional cost — including floor mixes, shed and road bases, landscaping, flooring, and structural materials. Imperial and metric, no sign-up.
Project calculators
Floor mixes, bases, sheathing, and insulation
Start with the job you are planning. Each link opens the closest existing calculator with the right measurements, formula, and product-yield guidance.
Deck mud & floor mud calculator
Estimate a mortar-bed volume from square feet and average thickness, then set the bag yield from your premix data sheet.
Self-leveling floor calculator
Turn floor area and average fill depth into volume and bags for self-leveling concrete or underlayment.
Shed base calculator
Size a gravel pad beyond the shed footprint and estimate the compacted base in cubic yards and tons.
Road base & sub-base calculator
Estimate crushed-stone road base from the compacted footprint and specified finished depth.
Roof & wall sheathing calculator
Convert roof, wall, or subfloor area into 4×8 plywood or OSB sheets with a cutting allowance.
Wall & attic insulation calculator
Calculate packages from insulated area, trimming waste, and the coverage printed on each product.
Calculators
All building material calculators
Enter your area and depth (or room size) and get the quantity, bags or tons, and an optional cost estimate in seconds.
Concrete Calculator
Slab, footing, and floor-leveler volume with adjustable bag yield.
Get your estimate in three steps
Step 1: Measure your area
Enter length and width (or the total square footage). Round, triangular and bordered shapes are supported where it matters.
Step 2: Set depth or thickness
Use the recommended default for your project — 3 in for mulch, 4 in for a concrete slab, 2 in for a gravel path — or enter your own.
Step 3: Read your quantity
Get cubic yards, tons, bags or boxes instantly — plus total cost if you add your local price per unit.
Done!
Why BuildCalc
Why estimate with BuildCalc
Estimates you can take to the supplier — and an honest note when a number is a range, not a fact.
Square feet, cubic yards and US tons by default, with a one-tap switch to m², m³, litres and tonnes.
Material densities and coverage rates are calibrated against published references and shown on every page, so you can check our math.
Every calculator is free and runs entirely in your browser. We never ask you to sign up or store the numbers you enter.
Beyond raw volume, we convert to the bags, boxes or tons you actually buy — and multiply by your price for a total.
FAQs
Building material calculator FAQs
How much area does a cubic yard cover?
One cubic yard spread 1 inch thick covers about 324 square feet. At a typical 3-inch mulch depth that drops to roughly 108 sq ft, and at a 2-inch gravel depth about 162 sq ft.
How many bags do I need?
It depends on the bag size. Mulch usually comes in 2 cu ft bags (about 13.5 bags per cubic yard), while an 80 lb bag of concrete mix yields roughly 0.6 cu ft, so it takes about 45 bags to make one cubic yard.
Should I add extra for waste?
Yes — for flooring and pavers we add a waste margin (about 10% for straight layouts, 15–20% for diagonal or herringbone patterns) so cutting and breakage do not leave you short.
How accurate are the estimates?
The geometry is exact, but bulk materials vary with moisture and gradation, so densities are typical mid-range values. We show the range on each page — order a little extra for full coverage.
Do you store the measurements I enter?
No. The calculators run in your browser and your inputs are never sent to or stored by us. See our Privacy Policy for details.
Can I use these for a contractor quote?
They are great for budgeting and ordering materials. For load-bearing or structural work, confirm depths and quantities against your local building code and your supplier.
Start your estimate
Pick your material, enter your measurements, and get the exact quantity to order — in seconds, for free.