480 sqft · 20×24 ft

20×24 Deck Cost

A 20×24 deck (480 sqft) is luxury-class — full outdoor kitchen + dining + lounge + grill island. The calculator below is pre-loaded with these dimensions — change the state, finish tier, or scope to recalculate live.

Get 2–3 free quotes

480 sqft88 ft perimeter5 finish tiersAll 50 states2026-Q1 pricing

20×24·Footprint

480·Sq ft

88·Perimeter ft

<2s·Live calc

How much a 20×24 deck costs by material

Material$/sqft installed20×24 total (480 sqft)

Pressure-treated wood

Cheapest to build; re-stain every ~2 years.

$25–$40$12,000–$19,200

Cedar / premium PT

Warmer look than PT; ages to silver, re-stain every ~3 years.

$35–$55$16,800–$26,400

Composite — mid-range

Trex Enhance, Fiberon Good Life. Wash-only; best 25-year value for most.

$50–$80$24,000–$38,400

Composite / PVC — premium

Trex Transcend, TimberTech AZEK. Longest warranty, coolest underfoot.

$75–$110$36,000–$52,800

Tropical hardwood (Ipe)

Ipe, Cumaru. Stunning and dense; pre-drill every fastener.

$90–$140$43,200–$67,200

A 20×24 deck is 480 sq ft. In pressure-treated wood that runs about $12,000–$19,200 installed — the cheapest way to get a deck this size, though you'll re-stain it every couple of years. Step up to mid-range composite (Trex Enhance, Fiberon Good Life) and the same 480 sq ft is $24,000–$38,400: roughly double the upfront, near-zero maintenance, and usually the lower 25-year cost.

Premium composite or PVC (Trex Transcend, TimberTech AZEK) lands around $36,000–$52,800, and tropical hardwood like Ipe tops out near $43,200–$67,200. These are installed (material + labor) for a simple rectangle — an L-shape adds ~10%, a wraparound ~22%, and a tall or hard-to-access deck up to 40%. Regionally, the South runs about 8% under these national figures and the West Coast about 28% over.

The calculator below itemizes a complete project — framing, footings, railing, stairs, permit, and contingency — so its total runs higher than the surface-and-labor bands above for the same size.

Inputs

Dimensions

Plan-view length × width.

Lengthft

Widthft

Area · 480 sq ft·Perimeter · 88 ft

Material tierinstalled $/sqft band

State2-letter · labor multiplier

Footprint shape1.00× complexity

AttachmentShares house structure

Deck heightinches

IRC R312 requires a 36″ guardrail above 30″.

Stairssteps

Site accessDriveway / wide-open backyard

Scope toggles

Project budget · Northeast

$36,084 – $63,434

$75–$132/ sq ft

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

Materials

Low $11,880

Labor

Low $17,714

Add-ons

Low $5,934

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″. 64 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

Materials30%$19,008
Labor45%$28,343
Add-ons15%$9,760
Soft costs1%$556
Contingency9%$5,767
Share of the high estimate. Switch tiers below to repaint the split.

Item

Qty

Total

Labor (Northeast, 1.22× national)

$17,714 – $28,343 (low – high estimate)

1.0 scope

$28,343

Labor (Northeast, 1.22× national)

$17,714 – $28,343 (low – high estimate)

1.0 scope

—

$28,343

Materials (decking + framing + hardware)

$11,880 – $19,008 (low – high estimate)

Home Depot Lowe’s

1.0 scope

$19,008

Materials (decking + framing + hardware)

$11,880 – $19,008 (low – high estimate)

Home Depot Lowe’s

1.0 scope

—

$19,008

Railing (64 lf, ledger 3-side)

$4,294 – $7,418 (low – high estimate)

1.0 scope

$7,418

Railing (64 lf, ledger 3-side)

$4,294 – $7,418 (low – high estimate)

1.0 scope

—

$7,418

Contingency (10% reserve)

up to $5,767

1.0 scope

$5,767

Contingency (10% reserve)

up to $5,767

1.0 scope

—

$5,767

Stairs (4 steps @ 9.0″ rise)

$1,640 – $2,342 (low – high estimate)

1.0 scope

$2,342

Stairs (4 steps @ 9.0″ rise)

$1,640 – $2,342 (low – high estimate)

1.0 scope

—

$2,342

Building permit (Northeast)

$556 flat

1.0 scope

$556

Building permit (Northeast)

$556 flat

1.0 scope

—

$556

Materials subtotal

$63,434

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…

DeckMath·24′ × 20′·480 sq ft

Trex Enhance·composite

Drag · pinch / scroll

Joists

19 × 20′

Beams

1 × 2-ply 2×10

Posts

4 × 6×6

Boards

44 rows

Project all-in

Materials (low – high)

Mid composite tier · Trex Enhance · Fiberon Good Life · TimberTech Prime+. ~$0.05/sqft/yr.

$11,880 – $19,008

Labor (installed)

Northeast · 1.22× national index

$17,714 – $28,343

Add-ons

Railing · stairs · lighting (only included items)

$5,934 – $9,760

Soft costs

Permit · demo · design (only included items)

$556 – $556

Contingency reserve (10%)

Industry-standard cushion for unforeseen scope

$5,767

Project total (low – high)

Plan around the high. Get 3 contractor bids — DeckMath should land within ±15%.

$36,084 – $63,434

Same dimensions, different tier

tap to switch

DIY savings

$29,845

vs mid-range contractor

Materials only: $19,008
Estimated hours: 720 hr
Skill required: advanced

Finance estimate

$1,286/month

60-month personal loan @ 7.99% APR

Principal: $63,434
Total interest: $13,720
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.

Estimated material takeoff — 20×24

The framing and decking a 20×24 (480 sqft) deck needs — board, joist, beam, post, footing, and railing quantities computed from the dimensions at 16″ joist spacing with a 10% waste factor.

Component

Quantity

How it's estimated

Decking boards (16′ × 5/4×6)

72 boards · 1152 lf

480 sqft ÷ 5.5″ face × 10% waste

Joists (2×8 @ 16″ o.c.)

19 joists · 380 lf

⌈24′ × 12 ÷ 16″⌉ + 1, each 20′ long

Beam lumber (3× 2-ply built-up)

144 lf

3 beam lines × 24′ × 2 plies

Posts (6×6 PT) + footings

12 posts · 12 footings

3 lines × (⌈24′ ÷ 8⌉ + 1) posts at ≤8′ o.c.

Footing concrete (60-lb bags)

63 bags · 28.3 cu ft

12 piers @ 12″⌀ × 36″ deep — adjust depth to local frost line

Joist hangers (Simpson LUS)

19 hangers

one per joist at the ledger / beam connection

Railing run

64 lf

88 lf perimeter − 24′ ledger side

Decking face screws

≈ 2,736 screws

≈2 screws per board at each joist crossing

Decking

72 boards

1152 lf incl. waste

Joists

16″ o.c. · 380 lf

Posts / footings

63 × 60-lb concrete

Railing

64 lf

88 lf perimeter

Estimated quantities for planning and budgeting — round up when ordering. Beam sizing, post spacing, and footing depth must follow your local code and a stamped plan (frost line, soil, and snow load vary by region per IRC 2021 / AWC DCA-6).

FAQ — 20×24 deck

How much does a 20×24 deck cost?

A 20×24 deck (480 sqft) costs $12,000-$19,200 for budget pressure-treated construction, $24,000-$38,400 for mid-range composite, and $43,200-$67,200 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 20×24 deck?

Running 5/4×6 or 1×6 deck boards (5.5″ face, 1/8″ install gap) parallel to the long dimension: rows = ceil(20 × 12 ÷ 5.625) = 43 rows. Total LF = 43 × 24 × 1.07 (7% waste, parallel pattern) ≈ 1105 LF. Round up to 20-ft stock for typical 56 boards.

How long does it take to build a 20×24 deck?

For a contractor crew (2-3 people), a 20×24 deck takes 5-8 days depending on complexity, including framing + decking + railing + inspection wait. DIY single-person build: 72-90 weekend days for composite, less for pressure-treated.

Do I need a permit for a 20×24 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 20×24 deck (480 sqft) exceeds the 200-sqft threshold and definitely requires a permit.