Deck Calculator
Estimate deck boards, joists and screws for any size deck.
Estimate deck boards, joists, and screws for a deck of any size. The deck calculator uses the deck dimensions, actual board width, board length, and joist spacing to estimate the required materials.
Deck boards
35
Joists
13
Screws
280
192 ft² deck
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Recommended tools & materials
Handy picks for this project on Amazon.
Speed Square
Fast angle and rafter layout
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Framing Nailer
Drive framing nails in seconds
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Construction Screws
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25 ft Tape Measure
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How does the deck calculator work?
Board count = (deck length ÷ board length) × (deck width in inches ÷ board actual width). A "5/4×6" board is really 5.5 in wide. Joists at 16 in on-center: (length in inches ÷ 16) + 1.
Which guide explains this in more depth?
- Riser-and-tread math plus 2026 material prices for a full stair build. Read the stair calculator cost breakdown guide for the full worked example.
What do people use the deck calculator for?
Deck for a 12×12 Deck
Estimate boards and fasteners for a 12×12 ft deck.
Deck for a 16×20 Deck
Estimate materials for a 16×20 ft deck.
Deck for a Pool Deck
Estimate materials for a pool surround deck.
Deck for a Second-Story Deck
Estimate materials for a second-story elevated deck.
Deck for a Ground-Level Deck
Estimate materials for a floating ground-level deck.
What else do people ask about this calculator?
How many deck boards for a 16×12 deck?
At 12 ft boards and 5.5 in actual width, about 27 boards plus 10% waste — order 30.
How far apart should deck joists be?
16 in on-center for standard decking; 12 in for composite or for spans over 12 ft.
Which related calculators should I use next?
All calculators
Gear Up for Your Deck Build
These practical tools and fasteners can help you measure, frame, and assemble your deck efficiently.
Metabo HPT Framing Nailer
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GRK Structural Screws
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DEWALT Impact Driver
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Paid links: as an Amazon Associate, MaterialCalc earns from qualifying purchases.