TheJobCalc — Free home-improvement calculators
Estimate exactly how much material a job needs before you drive to the store. Every calculator below works in US units or metric, adds a waste allowance, and converts the answer into the units suppliers actually sell in — cubic yards, bags, boxes, gallons and squares.
ConcreteCubic yards and bag counts for slabs, footings, columns and post holes.TileHow many tiles and boxes to buy, with grout joints and a cut allowance.Mulch & soilCubic yards, bags and weight for mulch, topsoil, compost and gravel.PaintGallons and cans for walls and ceilings, with doors and windows deducted.Square footageArea of any shape, added into a running total, with cost per square foot.Roof pitchPitch, angle, slope factor, roof area, squares and shingle bundles.
Why these numbers matter
Bulk material is priced by volume but sold in fixed packages, so a small measuring error turns into either a second trip or a pile of returns. A 10 × 12 ft patio poured 4 in thick needs 1.48 cubic yards of concrete; the same slab at 5 in needs 1.85. That single inch is seven extra 80 lb bags. The calculators here keep the arithmetic and the unit conversions out of your hands.
How the estimates are built
- Geometry first. Volume or area is computed from your measurements in feet, then converted — 27 cubic feet to the cubic yard, 144 square inches to the square foot.
- Waste allowance second. Cuts, spillage, uneven subgrade and breakage all cost material. Each tool has a default allowance you can change.
- Packages last. The result is rounded up to whole bags, boxes, gallons or bundles, because that is how you buy.
Latest guides
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