Square Feet to Linear Feet
Board widths change the answer: the same 200 sq ft deck needs 422 linear feet of 5.5" boards or 686 feet of 3.5" boards. Enter your board's face width to convert accurately.
Result
- Linear feet needed469lin ft
- Before waste426.7lin ft
- Coverage per lin ft0.4688sq ft
- 16 ft boards to buy30boards
- Metric143.1m
How it works
lin ft = area × 12 ÷ (face width + gap)
- Effective width = 5.5" + 0.125" = 5.625"
- Coverage per lin ft = 5.625 ÷ 12 = 0.46875 sq ft
- Linear feet = 200 ÷ 0.46875 = 426.67 ft
- + 10% waste = 469.33 ft → 30 boards at 16 ft
How the square feet to linear feet works
Coverage per linear foot is the board's face width plus the install gap, divided by 12 — the strip of floor each foot of board covers.
Divide your area by that coverage to get exact linear feet, then apply your waste allowance. Divide again by your stock length to find how many boards to buy.
Narrow boards need far more linear feet for the same floor: 3.5" boards need about 30% more length than 5.5" boards for identical area.
Formula
linear feet = area × 12 ÷ (face width + gap)
Worked example: 200 sq ft of 5.5" boards
- Effective width = 5.5" + 0.125" gap = 5.625"
- Coverage per linear foot = 5.625 ÷ 12 = 0.469 sq ft
- Linear feet = 200 ÷ 0.469 = 426.7 ft
- With 10% waste = 469.3 → 469 ft
- 16 ft boards to buy = ceil(469 ÷ 16) = 30
Linear feet per 100 sq ft by board width
| Board face width | With 1/8" gap | 100 sq ft | 200 sq ft |
|---|---|---|---|
| 3.5" (1×4) | 3.625" | 331 ft | 662 ft |
| 4" (1×5/fence) | 4.125" | 291 ft | 582 ft |
| 5.5" (5/4×6, 2×6) | 5.625" | 256 ft | 512 ft |
| 7.25" (2×8) | 7.375" | 195 ft | 391 ft |
| 5.5" no gap | 5.5" | 218 ft | 436 ft |
linear feet = area × 12 ÷ (width + gap), rounded up, without waste. Add waste for ordering.
Frequently asked questions
How many linear feet is 500 square feet of decking?
With standard 5.5" boards and a 1/8" gap: 500 × 12 ÷ 5.625 ≈ 1,067 linear feet before waste, or about 1,173 ft with 10%. Narrow 3.5" boards would need about 1,656 ft.
Why does board width change the linear feet?
Because each linear foot covers (width + gap) ÷ 12 square feet. Wider boards cover more per foot, so fewer feet are needed for the same area. The gap adds to the width because boards aren't laid flush.
Do I include the gap in the conversion?
Yes for decking and plank floors, which need drainage or expansion gaps — typically 1/8" to 3/16". For tongue-and-groove flooring laid without a gap, use the face width alone.
How do I convert back from linear feet to square feet?
Multiply linear feet by (face width + gap) ÷ 12. For example 500 lin ft of 5.5" boards with a 1/8" gap = 500 × 5.625 ÷ 12 = 234 sq ft.