Linear Feet Calculator
Calculate linear feet from an area and material width, or total the lengths in a cut list. Optional inputs can also estimate whole pieces and material cost.
Terminology: linear foot and linear feet describe length. “Lineal foot” is also used in some building-material contexts.
For rectangular coverage using constant-width material, first find area in square feet, convert the material width to feet, then use linear feet = area ÷ material width. For trim, fencing runs, or another cut list, add length × quantity for each item.
LF = area ÷ width in feet- Enter valid values above to see the arithmetic.
Linear Feet Formulas
The calculator uses unit conversion and basic length arithmetic rather than a material-specific rule of thumb.
Area to linear feet
For a rectangular area, area = length × width. If material width is entered in inches, width in feet = inches ÷ 12. Then linear feet = area ÷ width in feet.
Optional waste
If you enter a waste allowance, adjusted linear feet = raw linear feet × (1 + waste ÷ 100). No universal waste percentage is assumed.
Cut-list mode
For measured runs or pieces, total linear feet = Σ(length × quantity). This mode does not convert from area.
Whole-piece estimate
If a stock piece length is entered, the calculator uses ceiling(adjusted linear feet ÷ stock length). This is a purchasing approximation, not a cut-optimization algorithm.
Linear Feet vs. Square Feet vs. Board Feet
Linear feet is a length measurement. Square feet is an area measurement. Converting area to linear length therefore requires another dimension—the width of the material. For example, 100 square feet covered with material that is exactly 6 inches (0.5 ft) wide requires 200 linear feet before any added allowance.
Board foot is different again: the U.S. Forest Service defines a board foot as lumber volume represented by a piece 12 inches long, 12 inches wide and 1 inch thick, or its cubic equivalent. Do not substitute linear-foot results for board-foot quantities when lumber is priced by volume.
Linear Feet Calculator Examples
These examples use the same arithmetic as the calculator and do not assume a universal waste factor.
Area with 6-inch material
120 ÷ 0.5 = 240 linear feet before any optional waste allowance.
Same area with 10% entered
240 × 1.10 = 264 linear feet. The 10% is an example input, not a recommendation for every project.
Trim cut list
48 + 21 = 69 linear feet. At an illustrative $2.50 per linear foot, material cost would be $172.50.
What This Estimate Does Not Know
Installation layout can change material needs
Pattern, direction, seams, corners, openings, defects and cut reuse can affect how much stock is actually required. Use the manufacturer’s installation guidance when available.
Nominal and actual lumber dimensions differ
If coverage depends on actual face width, enter the actual width that will cover the surface rather than assuming the nominal product name is the usable width.
Whole-piece count is not cut optimization
Rounding total length up by stock length does not determine the most efficient cutting arrangement. A real cut plan can require more pieces depending on the individual required lengths.
Price basis varies
A supplier may quote per piece, linear foot, square foot, board foot, package or another unit. Confirm the pricing unit before using the cost field.
Linear Feet Calculator FAQ
How do I convert square feet to linear feet?+
Are linear feet and lineal feet the same?+
Does the calculator automatically add waste?+
What is a board foot?+
Why can the whole-piece estimate differ from a real cut list?+
How This Calculator Is Maintained
Umer Farooq
This page documents the formulas, unit assumptions and limitations used by the calculator. No independent professional review or construction credential is claimed.
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