How our deck calculator works

The formula in plain English

Every estimate combines five factors: square footage, material rate, height multiplier, regional labor adjustment, and extras(railings, stairs, add-ons, permits).

1. Square footage

Length × width. L-shaped decks are estimated at ~78% of the bounding rectangle.

2. Material rate per sqft

Each material has a low–high installed rate (60% material, 40% labor split). See our materials hub for the full table.

3. Height multiplier

Ground-level decks (×0.9), 2–4 ft (×1.0), 4–8 ft (×1.15), 8 ft+ (×1.30). Taller decks need more framing and footings.

4. Regional labor multiplier

Based on the first digit of your ZIP, labor is adjusted from ×0.90 (rural Midwest/South) up to ×1.20 (Northeast/West Coast metros).

5. Extras

• Railings priced per linear foot of perimeter, by railing type.
• Stairs at $75–$130 each.
• Permits at $150–$500 for decks over 50 sqft.
• Add-ons (benches, pergola, lighting, etc.) at fixed cost ranges.

How accurate is it?

Our estimates typically land within ±15% of real contractor quotes. Variance comes from local material availability, contractor backlog, site access, and finish details. Always get 2–3 written quotes before signing a contract.

Where pricing data comes from

We aggregate published rates from major decking manufacturers (Trex, TimberTech AZEK, Fiberon), HomeAdvisor and Angi market data, and contractor surveys. Pricing is reviewed monthly.