DeckMath
120 sqft · 12 × 10 ft

12×10 Deck Cost

A 10×12 deck (120 sqft) is the median small-deck size in the US — the most-permitted deck size for first-time builders. The calculator below is pre-loaded with these dimensions — change the state, finish tier, or scope to recalculate live.

120 sqft44 ft perimeter5 finish tiersAll 50 states2026-Q1 pricing
12×10·Footprint
120·Sq ft
44·Perimeter ft
<2s·Live calc

What a 12×10 deck costs by finish tier

Tier$/sqft (installed)Total range
Budget · Pressure-treated$25–$40$3,000–$4,800
Mid · Cedar / premium PT$35–$55$4,200–$6,600
Premium · Mid composite$50–$80$6,000–$9,600
Luxury · Premium composite$75–$110$9,000–$13,200
Exotic · Tropical hardwood$90–$140$10,800–$16,800

National-average pricing 2026-Q1. Northeast +22%, West Coast +28%, South -8%, Midwest baseline. Use the calculator below for precise state + scope adjustments.

Inputs

Dimensions

Plan-view length × width.

ft

ft

Area · 120 sq ft·Perimeter · 44 ft
in

IRC R312 requires a 36″ guardrail above 30″.

120 sq ft deck. Mid composite tier. Project total $11,505 to $20,030, 96 to 167 dollars per square foot.
Project budget · Northeast
$11,505 – $20,030$96–$167 /sq ft

120 sq ft · Mid composite · 1.22× labor · 1.10× complexity

Materials
Low $2,970
Labor
Low $4,429
Add-ons
Low $3,787
Soft costs
Permit · demo · design

Project advisories · IRC 2021

Guardrail included (deck 36″ off grade)

IRC R312

IRC R312 mandates a 36″ guardrail on open edges when deck height exceeds 30″. 32 lf priced at Mid composite tier.

Building permit included in budget

IRC R105

Northeast typical permit fee is in the budget. Most jurisdictions require a permit for decks > 200 sqft, > 30″ above grade, or attached to the house.

Hidden-fastener install premium baked in

Manufacturer specs

Mid composite uses hidden-fastener clip systems (Cortex / CamoClip / Trex Universal) — labor takes 25–30% longer than face-screwing PT. Already inside the tier's installed $/sqft band.

Cost breakdown

Labor (Northeast, 1.22× national)
$4,429 – $7,086 (low – high estimate)
1.0 scope
$7,086
Materials (decking + framing + hardware)
$2,970 – $4,752 (low – high estimate)
Home DepotLowe’s
1.0 scope
$4,752
Railing (32 lf, ledger 3-side)
$2,147 – $3,709 (low – high estimate)
1.0 scope
$3,709
Stairs (4 steps @ 9.0″ rise)
$1,640 – $2,342 (low – high estimate)
1.0 scope
$2,342
Contingency (10% reserve)
$0 – $1,821 (low – high estimate)
1.0 scope
$1,821
Building permit (Northeast)
$320 flat
1.0 scope
$320
Materials subtotal
$20,030

National-median pricing (2026-Q1). Local prices vary ±15%. Materials line uses Mid composite tier; switch tiers to repaint the budget. Includes 10% contingency reserve on the high estimate.

Live preview

Visualize your deck

Photoreal 3D · plan view · framing breakdown. Color matches your tier selection.

PBR materialsHDR lightingMid composite
Loading 3D scene…
12′ × 10′
Trex Enhance
Joists
10 × 10′
Beams
2 × 2-ply 2×10
Posts
6 × 6×6
Boards
22 rows

Project all-in

Materials (low – high)
Mid composite tier · Trex Enhance · Fiberon Good Life · TimberTech Prime+. ~$0.05/sqft/yr.
$2,970 – $4,752
Labor (installed)
Northeast · 1.22× national index
$4,429 – $7,086
Add-ons
Railing · stairs · lighting (only included items)
$3,787 – $6,051
Soft costs
Permit · demo · design (only included items)
$320 – $320
Contingency reserve (10%)
Industry-standard cushion for unforeseen scope
$1,821
Project total (low – high)
Plan around the high. Get 3 contractor bids — DeckMath should land within ±15%.
$11,505 – $20,030

Same dimensions, different tier

tap to switch

DIY savings

$10,346
vs mid-range contractor
  • Materials only: $4,752
  • Estimated hours: 180 hr
  • Skill required: advanced

Finance estimate

$416/month
60-month personal loan @ 8.99% APR
  • Principal: $20,030
  • Total interest: $4,912
  • Estimate only — shop 3+ lenders.
Composite/PVC installs use hidden-fastener clip systems — labor is 25–30% slower than face-screwing pressure-treated wood. That premium is already baked into the tier's installed $/sqft band.

Need exact board counts?

The Deck Material Calculator gives you a permit-ready bill of materials — every joist, hanger, fastener, and footing — validated against IRC 2021 span tables.

Open

Estimates use 2026-Q1 national-median pricing (Home Advisor, Angi, RSMeans). Expect ±15% variance vs your local market. Always get 3 contractor bids before signing. This calculator is not a substitute for a licensed inspector or structural engineer.

FAQ — 12×10 deck

How much does a 12×10 deck cost?

A 12×10 deck (120 sqft) costs $3,000-$4,800 for budget pressure-treated construction, $6,000-$9,600 for mid-range composite, and $10,800-$16,800 for premium composite or tropical hardwood. National-average pricing — multiply by 0.92× for the South or 1.28× for West Coast labor.

How many boards do I need for a 12×10 deck?

Running 5/4×6 or 1×6 deck boards (5.5″ face, 1/8″ install gap) parallel to the long dimension: rows = ceil(10 × 12 ÷ 5.625) = 22 rows. Total LF = 22 × 12 × 1.07 (7% waste, parallel pattern) ≈ 283 LF. Round up to 20-ft stock for typical 15 boards.

How long does it take to build a 12×10 deck?

For a contractor crew (2-3 people), a 12×10 deck takes 2-2 days depending on complexity, including framing + decking + railing + inspection wait. DIY single-person build: 18-23 weekend days for composite, less for pressure-treated.

Do I need a permit for a 12×10 deck?

In most US jurisdictions, yes. IRC 2021 R105 requires a permit for any deck above 30″ off grade, attached to the house, or larger than 200 sqft. A 12×10 deck (120 sqft) is below the 200-sqft threshold but most jurisdictions still require a permit if attached to the house or above 30″.

Other popular deck sizes

10×8
80 sqft
10×10
100 sqft
12×12
144 sqft
14×12
168 sqft
16×12
192 sqft
20×12
240 sqft
16×14
224 sqft
20×14
280 sqft
See all 20 deck sizes →