BuildCalc
Construction Tools
Online

The math your phone
calculator can't do.

Add feet, inches and fractions, lay out stairs to code, size up a concrete pour — free, right in your browser. No app to install, no sign-up.

Quick MathAdd and subtract feet, inches and fractions, plus instant unit conversions.
Stair CalculatorEven risers, the right tread depth and a stringer cut list — checked against code.
Concrete CalculatorHow much to order — cubic yards, bags and cost for slabs, footings and posts.
Roofing CalculatorRoof area, squares and shingle bundles from your footprint and pitch.
Decking CalculatorDeck boards, joists and screws for any rectangular deck.
Square Footage CalculatorTotal area in square feet, yards, meters and acres.
Gravel CalculatorCubic yards, tons and cost for gravel, stone or sand.
Drywall CalculatorSheets and screws to board out walls and ceilings.
Paint CalculatorGallons to paint a room, doors and windows subtracted.
Mulch CalculatorCubic yards and bags of mulch for any flower bed or garden.

Why not just use a phone calculator?

A phone calculator works in plain decimals. It can't add 5 ft 7 in to 2 ft 10-1/2 in, tell you how many 80 lb bags fill a footing, or flag a stair riser that fails code. BuildCalc is built for the measurements construction actually uses — feet, inches and sixteenths — so the numbers come out right the first time.

Free
No account
No install
Runs in browser
Offline
No signal needed

BuildCalc provides estimates for planning purposes only. Always verify results with a qualified professional and your local building code before purchasing materials or starting construction.

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