Common construction tasks
Combine rectangular areas for planning and pricing.
Open calculator Concrete CalculatorEstimate concrete volume from dimensions and quantity.
Open calculator Roofing CalculatorTranslate roof geometry into area and material planning.
Open calculator Feet and Inches CalculatorAdd and subtract tape-measure lengths in feet, inches and sixteenths.
Open calculatorHow to use these calculators
Construction calculators translate geometry into an order estimate. The result is only as reliable as the measurements and project model. Separate net dimensions from openings, overlaps, cuts, thickness and packaged coverage before purchasing materials.
Real projects also depend on local building codes, manufacturer instructions, structural design, soil, weather and workmanship. Use the calculator as a quantity check, retain a sketch with dimensions and ask the supplier how materials are sold. Structural, electrical, gas and life-safety decisions require the appropriate licensed professional and local authority.
Three checks that change the answer
Measure the installed geometry
Nominal room or lot dimensions may not capture slopes, openings, thickness and irregular edges.
Apply waste deliberately
Waste depends on pattern, cuts, breakage, batch size and installer experience rather than one universal rate.
Separate quantity from design
A material total does not verify span, load, reinforcement, ventilation or code compliance.
Before you use the answer
- Measure twice and preserve a dimensioned sketch.
- Use consistent units and actual thickness.
- Add project-specific waste and package rounding.
- Verify code, manufacturer and structural requirements.
Browse all 21 construction calculators
Every tool calculates in your browser. Pages marked “Reviewed guide” also include topic-specific explanations and source checks.
- Stair CalculatorReviewed guidePlan stair riser count, actual riser height, tread run, angle and stringer length.
- Roofing CalculatorReviewed guideEstimate sloped roof area, roofing squares, bundles and underlayment from footprint and pitch.
- BTU CalculatorReviewed guideEstimate room air-conditioner cooling capacity from area, ceiling height, occupants and room conditions.
- Area CalculatorReviewed guideFind the area of a rectangle, triangle, circle, trapezoid or ellipse, with the perimeter where it applies and conversions to other units.
- Square Footage CalculatorReviewed guideMeasure rectangular square footage, repeat areas, waste allowance and material cost.
- Concrete CalculatorReviewed guideEstimate concrete for a slab, footing or round column in cubic yards, cubic feet and 40, 60 or 80 lb bags, with an extra allowance.
- Tile CalculatorReviewed guideEstimate whole tiles for a rectangular surface, including waste.
- Mulch CalculatorReviewed guideEstimate landscape mulch volume from area, depth and an adjustable waste allowance.
- Gravel CalculatorReviewed guideEstimate gravel volume and mass from area, depth, material density and waste allowance.
- Paint CalculatorReviewed guideEstimate paint volume and container count from surface area, coats, coverage and waste.
- Drywall CalculatorReviewed guideEstimate drywall sheets from net wall or ceiling area, sheet dimensions and waste.
- Flooring CalculatorReviewed guideEstimate flooring area, packages and material cost across identical rooms.
- Fence CalculatorReviewed guideEstimate panels, posts and material length from fence run, openings and spacing.
- Deck CalculatorReviewed guideEstimate deck area, linear decking boards and whole boards from layout inputs.
- Asphalt CalculatorReviewed guideEstimate asphalt volume, mass and cost from paved dimensions, compacted depth and density.
- Rebar CalculatorReviewed guideEstimate a two-direction reinforcing grid, total bar length and mass from slab geometry.
- Topsoil CalculatorReviewed guideEstimate loose topsoil volume and mass from covered area, settled depth and compaction allowance.
- Sand CalculatorReviewed guideEstimate sand volume and mass from area, compacted depth, density and allowance.
- HVAC Load CalculatorReviewed guideProduce a preliminary heating or cooling load from floor area and editable load factors.
- Feet and Inches CalculatorReviewed guideAdd, subtract, multiply or divide lengths in feet, inches and fractions down to 1/16 inch, with decimal and metric equivalents.
- Acreage CalculatorReviewed guideConvert square feet to acres, or find the acreage of a lot from its length and width, with square yards, square meters and hectares.
Frequently asked questions
Should I order exactly the calculated amount?
Usually no. Packaging, cuts, breakage and future repairs may justify an explicit allowance.
Does a concrete volume include reinforcement?
No. Volume and reinforcement design are separate questions.
Can the stair calculator confirm code compliance?
No. Local rules cover geometry, landings, guards, headroom and other conditions.
Why does my supplier quote a different quantity?
Suppliers may round to full packages, use coverage rates or account for overlap and waste.
Reference starting points
Individual reviewed guides cite the equation or standard used by that calculator. These authorities provide broader context for this collection.