Decking Boards Calculator
Estimate how many deck boards you need for a deck. Enter the deck size, board width and the gap between boards, with boards running along the length.
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Estimate how many deck boards you need for a deck. Enter the deck size, board width and the gap between boards, with boards running along the length.
Worked example
Example calculated from the starting values. Enter your own values and press Calculate to get your result.
With the default inputs (deck length = 5 m, deck width = 3 m, board width = 90 mm, gap between boards = 5 mm), the results are: boards needed 32 boards; total board length 160.0 m.
Quick reference: deck length vs result
Reference table based on the example values; it is not your calculation result.
| Deck length (m) | Boards needed | Total board length |
|---|---|---|
| 2.5 | 32 boards | 80.0 m |
| 5 | 32 boards | 160.0 m |
| 10 | 32 boards | 320.0 m |
| 25 | 32 boards | 800.0 m |
| 50 | 32 boards | 1,600.0 m |
| 100 | 32 boards | 3,200.0 m |
Frequently asked questions
What formula does this calculator use?
Boards needed = ceil(w × 1000 ÷ (bw+gap)); Total board length = ceil(w × 1000 ÷ (bw+gap)) × l. Variables: l = deck length in m, w = deck width in m, bw = board width in mm, gap = gap between boards in mm.
What do I need to enter?
You need deck length (m), deck width (m), board width (mm), gap between boards (mm). Results update as you type.
What is an example result?
With the default inputs (deck length = 5 m, deck width = 3 m, board width = 90 mm, gap between boards = 5 mm), the results are: boards needed 32 boards; total board length 160.0 m.
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