Calculate how many deck boards you need, linear feet of decking, fasteners, and total cost for your deck project
Quality fasteners and tools make all the difference in deck longevity and appearance.
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To calculate deck boards: First, determine your deck's total width in inches. Divide by the actual board width plus the gap between boards to get the number of rows. Then multiply by the number of board lengths needed to span your deck length. Always add 5-15% for waste depending on your pattern and experience level. Our calculator handles all this automatically.
Choose board lengths that divide evenly into your deck length when possible. For a 16-foot deck, use 16-foot boards or 8-foot boards. For irregular dimensions, mixing lengths can help. For example, alternating 12' and 8' boards on a 20' deck minimizes cuts. Longer boards mean fewer joints but are heavier to handle and may have more curve or twist.
Wood decking (pressure-treated, cedar, or redwood) costs less upfront but requires regular staining/sealing. It lasts 15-25 years with maintenance. Composite decking costs 2-3x more initially but requires minimal maintenance and can last 25-50 years. Composite stays cooler in some cases but can get hot in direct sun. Consider your budget, maintenance preferences, and local climate when choosing.
Use 2 screws at each joist location where the board crosses. With joists 16" on center, a 12-foot board crosses approximately 10 joists, requiring about 20 screws per board. For a 16-foot board crossing 13 joists, you need about 26 screws. Deck screw boxes typically contain 350-1000 screws. Our calculator estimates total screws based on your deck dimensions and joist spacing.