Building a deck starts with the same question every time: how many boards do I actually need? Deck Calculator turns your deck size into a full material list — deck boards, joists, beams, posts and screws — and draws the deck from above so you can see the layout before you buy anything.
HOW IT WORKS
Type the width and length of your deck. Choose a board size, joist spacing and board direction with a tap. The plan view redraws instantly and the material list updates with it. No forms to submit, no waiting.
WHAT YOU GET
• Deck boards — how many pieces, based on board width and the gap between boards
• Joists — count and length for the spacing you choose (12", 16" or 24" on center)
• Rim joists and beams — the frame around and under the deck
• Posts — added when you enter a deck height, with the length including the buried part
• Deck screws — estimated by weight so you can grab the right box
• Total area in ft² — handy when you compare quotes
FEATURES
• Live plan view — boards, joists and the frame redraw as you change anything
• Board direction — flip between running across the width or along the length and watch the layout rotate
• Seam warning — if a row is longer than one board, the app tells you how many pieces per row so you can plan the seams
• Waste allowance — add 5% or 10% for cuts and defects, or keep the count exact
• Cost estimate — enter your local unit prices and see the running total
• Copy the list — one tap copies everything as text, ready to read at the store or paste into a message
• Save your decks — keep several layouts and reload them while comparing options
• Works offline — no account, no sign-up, nothing to load
BUILT FOR
• Homeowners planning a backyard deck
• Deck builders and landscapers pricing a job
• Anyone estimating lumber before a trip to the yard
NOTES ON ACCURACY
Joist count assumes joists at the spacing you pick plus one at the end. Beams and posts use a simplified layout, and board counts assume standard stock lengths. The numbers are an estimate to help you plan and shop — always confirm framing, footings and spans against your local building code and the conditions on your site before you order or build.
Enter your deck size and get the boards, joists and screws you need to buy.