From this site

One project, every trade

Each calculator adds its lines to a single estimate — consolidated BOM, schedule and cash-flow included.

Open My Project →

Deck Cost Calculator

Build a deck budget from its actual parts — surface, railing, footings and stairs — rather than one rate per square metre.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-27 · v1.0.0

Market
Imperial · sales tax
65.62 ft
Schematic, drawn to the proportions you entered — not to scale on screen.

Total deck cost

0 currency

Check your inputs

This calculator contains no market rates. Every rate is yours to supply, because a published national average is wrong for almost every individual project and budgeting against one is how projects run out of money.

Deck surface
0 currency
Railing
0 currency
Footings
0 currency
Stairs
0 currency
Contingency
0 currency
Cost per m² of deck
0 currency/m²
Railing share of the total
0 %

With the figures above, the total deck cost comes to 0 currency. Note that deck area and surface rate (per m², materials + labour) sit at the edge of the range this calculator was checked against, so treat the output as indicative rather than settled. The method behind this is well established, though site conditions and material batches will move it somewhat. This is calculated for United States and cites IRC 2024. Building in another market? Change the selector above so the units and code reference follow.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Element-based estimating. Rates are user-supplied; no market data is embedded.
  • Railing and stairs are priced per linear metre and per riser because their cost does not scale with deck area

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Frequently asked questions

Why not just use a cost per square metre?
Because two of the four biggest costs on a deck do not scale with area. Railing is priced per linear metre and a long thin deck has far more of it than a square one of the same area. Stairs are priced per riser and depend on how high the deck sits. A per-square-metre figure taken from someone else's deck silently imports their railing ratio and their ground level.
Which part usually costs the most?
Railing surprises people most often — on a small deck with open sides it can approach the cost of the surface itself. The breakdown shows railing as a percentage of the total for exactly this reason: if it is over about a third, the deck shape is driving the budget and a different plan may cost materially less for the same usable area.
Is composite worth the extra?
That is a maintenance-cost question over the deck's life, not a build-cost one. Composite boards cost substantially more up front and the substructure underneath is identical. Price both surface rates here and then weigh the difference against the staining and board replacement a timber deck needs over fifteen years.