Construction Calculators
Free building and remodeling calculators — concrete, tile, drywall, paint, flooring, roofing and more. Every result shows the formula behind it, so you always know where the numbers come from.
16 free calculators
Concrete & Masonry
Concrete Calculator
Cubic yards, bags and truckloads for any pour.
Use calculator →Concrete Bag Calculator
Bag counts for small pours and post holes.
Use calculator →Retaining Wall Calculator
Blocks, caps, gravel and drain pipe per wall.
Use calculator →Grout Calculator
Grout bags from tile size and joint width.
Use calculator →Flooring & Tile
Walls & Finishing
Drywall Calculator
Sheet, screw and mud counts for walls and ceilings.
Use calculator →Paint Calculator
Gallons of paint and primer per room, by coats.
Use calculator →Wallpaper Calculator
Rolls and strips with pattern-match waste.
Use calculator →Insulation Calculator
Batts, bags and R-values for attics and walls.
Use calculator →Outdoor Projects
Complete Guide to Construction Calculators
How to get the most from our building tools — and answers to common questions.
How to use our construction calculators
Every tool on this page follows the same simple flow. Pick the calculator for your project, enter your measurements, and get instant material quantities — no sign-up, no downloads, everything calculated right in your browser.
- Measure carefully. Every calculator is only as good as the numbers you enter. Measure twice, in feet or inches as the tool asks, and double-check room dimensions before ordering materials.
- Set the right waste factor. Cutting and fitting always wastes material. Use 5% for simple rectangles, 10% for standard rooms, and 15% for diagonal patterns, irregular shapes, or hand-dug work.
- Round up to whole units. You buy whole bags, boxes, sheets, and bundles — the calculators round up for you, so the result is your actual shopping list.
- Compare before you buy. Change your inputs to compare scenarios side by side — bagged concrete vs. ready-mix, for example — and pick the cheaper option.
Tips that save real money
Material is usually the biggest cost on a DIY project, and small estimating mistakes compound fast. A few rules of thumb from the guides on each calculator page:
- Concrete: under about 2 cubic yards, bagged mix is often cheaper than paying a ready-mix delivery minimum plus short-load fee.
- Tile and flooring: buy all boxes from the same dye lot at once — a second batch can be a visibly different shade.
- Paint: one gallon covers roughly 350 square feet per coat; primer matters on bare drywall and patched spots.
- Lumber: board feet is thickness × width × length ÷ 12 — the number every lumberyard prices from.
Construction calculator FAQs
Are these calculators really free?
Yes — every calculator is 100% free, with unlimited use and no sign-up required.
How accurate are the material estimates?
They use standard trade formulas and round up to whole purchasable units. Real-world waste varies with layout complexity, so treat the result as a solid shopping list and keep receipts for returns.
Do the calculators work on mobile?
Yes — handy on-site. Every tool is fully responsive and works on phones, tablets, and desktops.
Is my data private?
Yes. All calculations happen in your browser — your measurements are never sent to our servers or stored anywhere.
Popular construction calculators
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