How many deck screws or hidden clips do you need? Enter the deck size and the fastener type. You get the number of fasteners and boxes to buy.
Your shopping list
744Fasteners to buy
3Boxes to buy
13Joists
- Rows of boards26
Use deck screws made for outdoor use. Extra of 10% is included.
How to use the Deck Screws and Fasteners Calculator
- Enter the deck length and width.
- Pick the board width and joist spacing.
- Choose screws or hidden clips, type how many come in a box and read the boxes to buy.
The math behind it
Fasteners = rows x joists x fasteners per crossing x (1 + extra %)
Boxes = fasteners / fasteners in one box, rounded up
A worked example
What we typed in
- Deck length: 20 ft
- Deck width: 14 ft
- Board width: 5.5 in wide (5/4 x 6 or 2×6)
- Joist spacing: 16 in apart (standard)
- Fastener type: Hidden clips (1 per board at each joist)
- Fasteners in one box: 500
- Extra for mistakes and cuts: 10%
What we got
- Fasteners to buy: 528
- Boxes to buy: 2
- Joists: 16
- Rows of boards: 30
Tips from the job site
- Face screws use 2 per board at each joist. Hidden clips use 1.
- Buy deck screws rated for outdoor use and for your wood or composite board.
Common questions
How many deck screws do I need for a 12 x 16 deck?
About 744 screws with 5.5 in boards, joists 16 in apart and 10% extra. That is about 3 boxes of 350.
How many screws go in each board?
Two screws at every joist the board crosses, one near each edge.
See all Deck Calculators.
Last checked: (worked example and form display).