The Deck Calculator helps you estimate deck boards needed for your project. Simply fill in the fields above and click Calculate to get an instant result.
This calculator is part of Calculate Wiki’s Construction Calculators collection.
What You’ll Need
- Deck Length (ft)
- Deck Width (ft)
- Board Width (in)
- Gap Between Boards (in)
- Board Length Available (ft)
- Waste Allowance (%)
Formula Used
Rows across width = (Width in inches) ÷ (Board width + gap)
Total linear feet = Rows × Length × (1 + Waste %)
Boards needed = Total linear feet ÷ Board length
Example Calculation
Using example inputs — Deck Length = 16 ft; Deck Width = 12 ft; Board Width = 5.5 in; Gap Between Boards = 0.25 in; Board Length Available = 12 ft; Waste Allowance = 10 % — the Deck Calculator returns:
| Value | Result |
|---|---|
| Deck area | 192 sq ft |
| Total linear feet of boards | 441 ft |
| Boards needed (12 ft each) | 37 |
37 deck boards. Deck area: 192 sq ft, using 12 ft boards.
Helpful Information
Results from the Deck Calculator are estimates based on standard formulas used in the construction calculators field. For projects with significant cost, health, or safety implications, consider verifying results with a qualified professional.