DDeckCalcHQ

Deck calculators

Each tool reads the real IRC R507 deck span tables. Start with whichever part of the deck you're sizing — they all run on the same code-compliant engine.

Deck Joist Span Calculator (IRC R507.6)
deck joist span calculator · 2,400/mo searches

Free deck joist span calculator — find the maximum span for 2x6, 2x8, 2x10 and 2x12 joists at 12, 16 or 24 inch spacing, straight from the IRC R507.6 deck table.

Deck Beam Span Calculator (IRC R507.5)
deck beam span calculator · 720/mo searches

Free deck beam span calculator — how far a 2-ply or 3-ply 2x8/2x10/2x12 deck beam can span between posts, from the IRC R507.5 table, based on the joist span it carries.

Deck Footing Size & Depth Calculator
deck footing calculator · 1,300/mo searches

Free deck footing calculator — get the footing diameter from your post load and soil bearing, the depth below your state's frost line, and the concrete (bags) each pier needs (IRC R507.3).

Deck Stair Calculator — Risers, Treads & Stringers
deck stair calculator · 3,600/mo searches

Free deck stair calculator — enter your deck height to get the number of risers, the exact riser height, tread run and total stair run to IRC R311.7 code.

Deck Cost Calculator — What Will My Deck Cost?
deck cost calculator · 1,600/mo searches

Free deck cost calculator — estimate the cost to build your deck by size and material, from a DIY lumber budget up to a contractor-installed price.

Deck Material Calculator — Boards, Screws & Lumber
deck material calculator · 1,900/mo searches

Free deck material calculator — how many deck boards, screws and lineal feet of framing your deck needs, plus a material cost estimate by decking type.

Deck Railing & Baluster Spacing Calculator
baluster calculator · 1,600/mo searches

Free deck railing & baluster spacing calculator — get the exact number of balusters and an even gap that passes the IRC 4-inch sphere rule for your railing length.