Buying shiplap siding, hardwood decking boards, baseboard molding, or rolled vinyl sheet flooring? While home floor plans and wall surfaces are measured in square feet, lumberyards and trim manufacturers sell materials strictly by the linear foot.
You cannot convert square feet directly to linear feet without knowing one crucial dimension: the material's width. A 4-inch wide board requires three times as many linear feet to cover the same room as a 12-inch wide board. This guide explains the conversion formulas and provides a live material width converter.
The Linear Foot Conversion Formulas
Converting Square Feet to Linear Feet
Linear Feet = Square Feet ÷ (Width in Inches ÷ 12)
Converting Linear Feet to Square Feet
Square Feet = Linear Feet × (Width in Inches ÷ 12)
Visual Width Comparison
How Board Width Dictates Linear Footage
Live Square Feet to Linear Feet Converter
Interactive Tool
Interactive Material Width & Length Tool
Linear Feet Needed
655 Linear Feet
Includes 10% cut scrap (720 LF recommended)
8-Foot Boards:
90 Boards
12-Foot Boards:
60 Boards
Nominal vs. Actual Lumber Widths
Always remember that lumber is sold by nominal size, but finished dressed lumber is significantly smaller:
| Nominal Size | Actual Dressed Width | Linear Feet Per Sq Ft | LF for 500 Sq Ft |
|---|---|---|---|
| 1×4 board | 3.5 inches (0.292 ft) | 3.43 LF | 1,714 LF |
| 1×6 decking | 5.5 inches (0.458 ft) | 2.18 LF | 1,090 LF |
| 1×8 shiplap | 7.25 inches (0.604 ft) | 1.65 LF | 825 LF |
| 1×10 fascia | 9.25 inches (0.771 ft) | 1.30 LF | 650 LF |
| 1×12 shelving | 11.25 inches (0.938 ft) | 1.07 LF | 535 LF |
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