How Many Boards for an 8x8 Deck?
Deck boards to buy
9 16 ft boards
64 square feet, 17 rows of decking, joists 16 inches on center.
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How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Deck length8 ft
- Deck width8 ft
- Board face width5.5 in
- Gap between boards0.25 in
- Board length you buy16 ft
- Joist spacing on center16 in
Deck boards to buy9 16 ft boards
| Deck area | 64 sq ft |
|---|---|
| Board rows across the width | 17 |
| Linear feet of decking | 136 lf |
| Boards at 16 ft | 9 |
| Joists at 16 in on center | 7 |
The material list this produces
| Deck boards, 16 ft | 9 |
|---|---|
| Joists, 8 ft | 7 |
| Joist hangers, each | 14 |
| Deck screws, lb | 2 |
Board length compared
Same deck, four board lengths. Longer boards mean fewer end joints and more offcut risk.
| Board length | Deck boards to buy |
|---|---|
| 8 ft boards | 17 8 ft boards |
| 12 ft boards | 12 12 ft boards |
| 16 ft boards | 9 16 ft boards |
| 20 ft boards | 7 20 ft boards |
What else matters here
Seventeen rows at 8 feet is 136 linear feet. Bought as 16 foot boards and cut in half that is 9 boards. Bought as 8 foot boards it is 17, because each one only makes one row.
Nine boards against seventeen is the whole point of this page. The linear footage is identical either way, so the saving is not in the wood, it is in the price break: decking is priced per foot and the per foot price on a 16 usually sits below the per foot price on an 8, because the mill gets more usable length out of the log.
It is not automatic. Check the two per foot prices at the yard before assuming, because some yards price 16s at a premium for handling, and 16 foot boards in the back of a pickup are their own problem. But on an 8 by 8 the check takes a minute and it is the largest single lever on the material bill.
What this calculator assumes
- A nominal 2x6 board is 5.5 inches of actual face. Nominal sizes are not real sizes, which is where most deck orders go wrong.
- Joist count is the span across the deck width at the spacing given, plus one for the last joist.
- Waste is not added. Add 5 to 10 percent if the deck is not a plain rectangle.
Questions people ask
How many boards for an 8x8 deck?
Nine boards of 5/4 by 6 at 16 feet, each cut in half. Seventeen boards if you buy 8 foot stock instead.
Is it cheaper to buy 16 foot deck boards and cut them?
Usually, because the per foot price on a 16 is often lower than on an 8. Compare the per foot prices at the yard rather than the price per board.
How many joists for an 8x8 deck?
Seven at 16 inches on center, each one 8 feet long, plus the rim.
The deck calculator takes any dimensions you like and hands back the same list.