Construction calculators
Site and finish takeoffs from the numbers you type. Every page here is an estimate. None of them is structural design, a permit, or code approval.
12 tools
In this group
Bulk volume: concrete, gravel, and mulch. Area: square footage and land area. Finish counts: paint and tile. Geometry: stairs, roof pitch, roof area, tank volume, and grade.
Estimates, not structural design
Waste, bags, and gallons help you plan a purchase. They do not size beams, mix psi, stair code, or a legal lot. Confirm with a supplier, a builder, or a surveyor where the job binds you. See the disclaimer.
- Land Area Calculator Rectangle arithmetic for lots: square feet, square meters, acres, and hectares. A surveyor is required for a legal area. This is not a GIS map and not a plat.
- Concrete Calculator Slab volume is length times width times depth. A cylinder is π r² h. Cubic yards divide cubic feet by 27. Waste is 0 to 50 percent. This is an estimate, not structural design or code approval.
- Grade Calculator Site grade is rise divided by run. You get percent grade, a 1:x ratio, and an angle. This is not a survey plat. Math slope between two points and roof pitch live on other URLs.
- Gravel Calculator Box volume for crushed stone or gravel. Cubic yards divide cubic feet by 27. Optional tons use a density in lb/ft³ you type. This is coverage, not a concrete mix design.
- Mulch Calculator Bed volume for landscaping mulch. Depth is often 2 to 3 inches. Cubic yards divide cubic feet by 27. This is coverage, not a soil test.
- Paint Calculator Wall area is 2 × (length + width) × height. Doors subtract 20 ft² each. Windows subtract 15 ft² each. Gallons are net area times coats divided by coverage, then rounded up to buy. Estimate only.
- Roof Area Calculator Plan length times width, then multiply by hypot(run, rise) divided by run. That is a simple gable from a rectangular plan. Estimate only, not a full takeoff.
- Roof Pitch Calculator Pitch is rise over run, shown as x:12, degrees, and percent. The area factor is hypot(1, rise/run). Multiply a plan area by that factor. Estimate only, not code approval.
- Square Footage Calculator Floor area from rectangles you type. One room uses length and width. Several rooms go in the list, one pair per line. Output is ft², m², acres, and hectares. Estimate only. This is not a survey or code approval.
- Stair Calculator Risers are ceil(total rise / max riser), at least 2. Treads equal risers minus 1. Optional total run yields tread depth and 2R+T. This is not building-code approval.
- Tank Volume Calculator Vertical cylinder, horizontal cylinder with a circular segment fill, or a rectangular box. Output is m³, liters, and US gallons. The manufacturer stamp wins. This is not a pool-volume calculator.
- Tile Calculator Room area divided by one tile, then waste up to 40 percent, then a whole-tile buy count. Pattern layout can raise waste. Estimate only.