Construction math that's right the first time.
Fast, accurate calculators for concrete, decking, stairs, and more — built for tradespeople and serious DIYers. No "estimate by vibes." Real formulas, real units, real answers.
Calculators
6 tools · more every weekConcrete Calculator
Volume in cubic feet and yards, bags by size, and estimated cost — with waste built in.
Most used →Deck Beam & Joist Span
IRC 2021 table lookups for max joist and beam spans — by species, size, and spacing.
IRC tables →Stair Stringer Calculator
Riser height, tread run, and stringer length — code-checked for residential stairs.
Framing →Deck Board Spacing
Boards needed for your deck surface, with even gaps and waste allowance.
Decking →Gravel & Mulch Calculator
Yards, tons, bags, and cost for gravel, mulch, sand, and topsoil beds.
Landscaping →Drain Pipe Slope Calculator
Fall per foot and total drop for sanitary pipe — IPC 704.1 checked.
Plumbing →Pick your tool
Concrete, framing, stairs, landscaping — whatever you're building.
Enter your numbers
Feet, inches, spacing, waste. The units you actually work in.
Get a code-checked answer
Results from published tables and formulas — with the code rule stated.
Coming next
On the benchNew tools ship every week — verified against code tables and manufacturer specs before they go live.