Decking Calculators
Plan your deck build with accurate material estimates. Our deck calculator turns your dimensions and board size into deck boards, joists, screws, and an installed-cost range — for pressure-treated wood, cedar, or composite. Explore the tool and cost guides below.
Decking calculators
What you can estimate
- Deck boards and framing
- Joists and fasteners
- Cost by decking material
- Wood vs composite pricing
How to estimate deck materials
A deck estimate starts with the surface area — length × width — but the board count depends on the size of the decking you choose and the direction you run it. Divide the deck area by each board's coverage and add 5–10% for waste and cuts. Then there's the frame below: joists spaced 16 inches on center, beams, posts, and a footing at each post, plus hidden fasteners or screws.
Our deck calculator pulls all of this together — deck boards, joists, fasteners, and an installed-cost range — from your dimensions and chosen material, so you can plan a pressure-treated, cedar, or composite build without guesswork.
Decking material comparison
The big decision is wood versus composite. Pressure-treated wood is cheapest upfront but needs regular sealing; composite costs more but barely needs maintenance and lasts decades.
| Material | Cost / ft² (installed) | Maintenance | Lifespan |
|---|---|---|---|
| Pressure-treated wood | $15 – $25 | Seal every 1–2 yrs | 10–15 yrs |
| Cedar / redwood | $20 – $35 | Seal periodically | 15–20 yrs |
| Composite | $25 – $45 | Rinse only | 25–30 yrs |
Deck-building tips
- Space joists 16 inches on center for standard decking.
- Use hidden fasteners with grooved composite boards for a clean look.
- Set posts on proper footings below the frost line.
- Add 5–10% to your board count for waste and picture-frame borders.