FreeConstructionCalculators
17 free calculators · no sign-up

Estimate any build in seconds.

Accurate material calculators for builders, contractors and DIYers — concrete, roofing, drywall, paint, gravel, wiring and more.

Popular:ConcreteRoofingDrywallPaintGravel

Concrete & masonry

Concrete CalculatorCubic yards and 40, 60 or 80 lb bags for slabs, footings, columns and steps. Retaining Wall CalculatorBlocks, caps, and base and drainage gravel for a block retaining wall.

Landscaping & outdoor

Gravel CalculatorCubic yards and tons of gravel, crushed stone, sand or road base. Mulch CalculatorCubic yards or bags of mulch for any bed, with bagged vs bulk cost. Fence CalculatorPosts, rails, pickets and concrete for any fence length and spacing. Pool Volume CalculatorGallons and liters for rectangular, round and oval pools, plus fill time.

Carpentry & roofing

Roofing CalculatorRoof area, squares and shingle bundles from footprint and pitch. Stair CalculatorRisers, treads, stringer length and angle with IRC code checks. Board Foot CalculatorBoard feet and cost for hardwood and dimensional lumber.

Interior finishing

Drywall CalculatorDrywall sheets for walls and ceilings, plus mud, tape and screws. Paint CalculatorGallons of paint for walls and ceilings, with coats and openings. Tile CalculatorTiles and boxes for floors and walls, including grout joints and waste.

Electrical & HVAC

Wire Size CalculatorAWG wire size by amps, distance and voltage drop (NEC tables). BTU CalculatorAir conditioner size in BTU for any room (ENERGY STAR method). Solar Panel CalculatorSolar system size, number of panels, roof space and payback.

Area & measurement

Square Footage CalculatorTotal area of rooms, lots and odd shapes in sq ft, sq yd, m² and acres.

Contractor business

PTO CalculatorPaid time off accrual per pay period, per hour, and future balance.

How it works

1

Pick a calculator

Choose the job — a slab, a roof, a room to paint — from 17 specialist tools.

2

Enter your measurements

Feet and inches or meters and centimeters. Results update as you type.

3

Order with confidence

Get quantities in the units suppliers sell — yards, tons, bags, sheets, gallons — with waste included.

Standard formulasEvery page shows the math, so you can check it.
Code-awareStair, wire and wall tools flag common code limits.
Mobile-firstBuilt to use on the job site, on any phone.
Always freeNo account, no data stored, no paywall.