Roofing & Insulation
How Many Bundles of Shingles Do I Need? Squares, Waste and Extras
Work out shingle bundles from roof area using squares, bundles per square and 10–15% waste, plus starter strip and ridge cap. Free calculator and example.
Measure · Estimate · Build
How much do you need? Work it out before you drive to the store.
Free calculators and plain-English guides for concrete, gravel, paint, tile, decks and more. Every formula is shown, every product figure links to the manufacturer.
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Pick your project
Landscaping & YardGravel, mulch, soil, pavers, sod and seed.
Concrete & MasonryBags, yards, slabs, post holes and block walls.
Flooring & TileTile, grout, thinset, plank flooring and carpet.
Paint & WallsPaint, primer, drywall, joint compound and wallpaper.
Decks & FencesDeck boards, joists, screws, stain, posts and pickets.
Roofing & InsulationShingles, roof area and attic insulation.
Latest guides
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Roofing & Insulation
How Much Attic Insulation Do I Need? R-Values, Depth and Bags
Find the attic R-value ENERGY STAR recommends for your climate zone, then turn it into bags of blown-in insulation with a free calculator and coverage chart.
Decks & Fences
How Many Fence Posts Do I Need? Spacing, Gates and Corners
Count fence posts from your fence length, post spacing, gates and corners. Free calculator, a quick chart, hole depth guidance and layout tips.
Decks & Fences
How Many Deck Boards Do I Need? Rows, Lengths and Gaps
Count deck boards by rows and board length, not just square feet. Free calculator, a chart for common deck sizes, gap sizes and joint layout tips.
Flooring & Tile
How Many Boxes of Flooring Do I Need? Calculator and Chart
Turn room square footage into boxes of laminate, vinyl plank or engineered wood. Free calculator, a box chart, a worked example and why to keep a spare box.
Flooring & Tile
How Much Grout Do I Need? Pounds and Bags by Tile and Joint Size
Estimate grout in pounds and bags from tile size, thickness and joint width. Free calculator, joint-volume formula, coverage chart and sanded vs unsanded.
Flooring & Tile
How Much Tile Do I Need? Tiles, Boxes and Waste by Layout
Work out how many tiles and boxes to buy for a floor or wall. Free calculator, a chart for common tile sizes and waste for straight, diagonal and herringbone.
Paint & Walls
How Many Sheets of Drywall Do I Need? 4×8 vs 4×12 Sheets
Count drywall sheets for walls and ceilings in 4x8, 4x10 or 4x12 sizes. Free calculator, a chart by room size, the formula and a screw estimate.
Paint & Walls
How Much Exterior Paint Do I Need? Gallons for Your House
Estimate gallons of exterior paint for your house, including gables, doors and windows. Free calculator, a chart by house size and tips for rough siding.
What you can expect here
The math, out in the open
Each calculator shows its formula and a worked example, so you can check the answer with a tape measure and a phone calculator.
Numbers from the label makers
Bag yields, coverage rates and spacing rules come from manufacturers, building-science agencies and university extension services, and each one is linked.
Honest about the limits
An estimate is not an engineered plan. Where codes, permits or structural loads matter, we say so and point you to the right professional.