Free home and DIY project calculators
Estimate materials and measurements for your next project: concrete and slabs, volume, area, paint, gravel, mulch, lumber, stairs and voltage drop. Every page shows its formula, assumptions and sources, plus metric results.
Home & DIY calculators
Concrete and landscaping
Concrete Calculator (Bags and Cubic Yards)Estimate concrete for a slab, footing or post holes in cubic yards, cubic feet and cubic meters, and how many 40, 60 or 80 lb bags of mix you need.Concrete Slab and Pad CalculatorEstimate concrete for a slab, patio or pad, including an optional thickened edge and several identical slabs, in cubic yards, m³ and premixed bags.Cubic Yards and Cubic Feet CalculatorCalculate cubic yards and cubic feet for a box-shaped or round space, or convert between cubic feet, cubic yards, cubic inches and cubic meters.Gravel Calculator (Cubic Yards and Tons)Estimate gravel or crushed stone for a driveway, path or pad in cubic yards, cubic meters, tons and metric tonnes, with a waste allowance.Mulch Calculator (Cubic Yards and Bags)Estimate mulch for garden beds in cubic yards, cubic feet and bags from bed size and depth, using the extension-service 324 sq ft rule.
Building and finishing
Square Footage CalculatorCalculate square footage for rectangles, triangles, circles and trapezoids in feet or meters, with square yards, square meters and an optional waste allowance.Paint CalculatorEstimate how much paint you need for a room's walls (and ceiling) from its size, doors, windows, number of coats and the coverage on your paint can.Board Foot CalculatorCalculate board feet for lumber from thickness, width, length and piece count, with a waste allowance, optional price per board foot and cubic meters.Stair Calculator (Rise and Run)Calculate the number of stair risers and treads, riser height, total run, stringer length and angle from the total rise, in inches or centimeters.
Electrical
How we keep it accurate
Formulas use exact unit conversions from NIST and published figures from manufacturers, extension services and state transportation departments, and every calculator is checked with automated test cases. Results are estimates: confirm quantities with your supplier and check local codes. Read more about JobsiteCalc.