Linear Feet Calculator
How do I convert square feet to linear feet? Divide your total area by the material width in feet. This calculator handles lumber, flooring, siding, and fencing with built-in waste factors so you know exactly how much to buy.
Conversion
10% for straight cuts, 15-20% for angles/patterns
Ready to convert
Enter your measurements
Last updated June 22, 2026 by our expert review team
Stock-Length Optimizer
Which board length wastes the least? Most calculators won't tell you.
Use the result from the converter above (includes waste).
Buy 22 boards at 8' = 176 LF purchased, only 3 LF leftover (1.7% waste). Mixing two lengths can trim leftover further on odd totals.
Leftover assumes no end-to-end joining; real waste is lower if you splice offcuts.
Common Material Widths
Lumber/Boards
Decking, framing
Flooring Planks
Hardwood, LVP
Siding
Lap siding
Trim/Molding
Baseboards, crown
Fabric/Carpet
Rolled goods
Fence Boards
Privacy fence
Expert Contributors
Cherry Jane Limbago
Licensed Civil Engineer & Master Plumber
Licensed civil engineer and master plumber with 10+ years in structural design, estimation, and project management. Currently Project Engineer at Universal Robina Corporation.
See full profileHawkin
Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
See full profileUpdated June 2026
How we verify our calculatorsQuick Conversion Reference (100 sq ft to linear ft)
| Material Width | Linear Feet | +10% Waste | 8' Boards |
|---|---|---|---|
| 3.5" (1×4) | 343 | 377 | 48 |
| 5.5" (1×6) | 218 | 240 | 30 |
| 7.25" (1×8) | 166 | 182 | 23 |
| 9.25" (1×10) | 130 | 143 | 18 |
| 11.25" (1×12) | 107 | 117 | 15 |
Area Divided by Actual Width
Linear feet depends on the usable width that covers the surface. Nominal lumber size, overlap, tongues, and grooves can all change the width you should enter.
Use the actual coverage width from the material label when it differs from the nominal board or roll size.
Pro Tips
Always use actual lumber widths, not nominal. A '1x6' board is actually 5.5" wide, so using the nominal 6" overestimates coverage by 8.3% and leaves you short.
Standard carpet rolls come in 12 ft and 15 ft widths. Choose the width closest to your room dimension to minimize seams.
For hardwood flooring, common plank widths are 3.25" (Bruce), 5" (Shaw), and 7" (Mannington). Wider planks need 2-3% less linear footage but cost 15-25% more per sq ft. Use our flooring calculator to estimate boxes and costs after converting your room measurements.
When calculating trim, measure each wall individually and add 10% for miter cuts. A typical 12x14 ft room needs about 52 linear feet of baseboard.
Fabric and vinyl rolls come in fixed widths: 54" for upholstery, 36" for craft, and 6 or 12 ft for sheet vinyl. Divide square footage by roll width in feet for running length.
For diagonal flooring at 45 degrees, add 15 to 20% waste instead of the standard 10%. Angled cuts generate significantly more unusable offcuts.
Need to calculate the area first? Our square footage calculator handles rectangles, circles, triangles, and L-shapes.
How the Calculator Works
Linear feet is a buying length. Square feet is a coverage area. To convert between them, the calculator first turns the material width into feet, then divides area by that width. A 5.5 inch board covers 0.458 feet of width, not 6 inches.
The width you enter should be the actual coverage width. For decking and lumber, that is usually the dressed board width. For tongue-and-groove flooring or lap siding, use the exposed face after overlap. For carpet, vinyl, or fabric rolls, enter the roll width in feet.
Waste is added after the conversion. Straight runs may need 5 to 10%. Trim with miters, diagonal flooring, herringbone, and rooms with closets or jogs often need 15 to 20%. If the material is priced by board foot instead of linear foot, use the board foot calculator after you know the linear feet.
Formulas
Linear Feet = Square Feet ÷ Width (in feet)
Square Feet = Linear Feet × Width (in feet)
Order length = result × (1 + waste%), then round to sellable board or roll lengths
Pro tip: When ordering from lumber yards, convert your linear feet to board count by dividing by the standard board length (8, 10, 12, or 16 ft) and rounding up. Mixing 8 ft and 12 ft boards often reduces waste by 10-15% compared to using a single length.
Nominal vs Actual
- 1×4 actual
- 3.5"
- 1×6 actual
- 5.5"
- 1×8 actual
- 7.25"
- 1×10 actual
- 9.25"
- 1×12 actual
- 11.25"
Frequently Asked Questions About Square Feet to Linear Feet
What width should I enter for lumber?
Enter actual dressed width. A nominal 1x6 is usually 5.5 inches wide. If the board has a profile, use the exposed coverage width from the label or manufacturer data.
How does this work for carpet or sheet vinyl?
Use the roll width in feet. A 180 sq ft room with 12 ft carpet needs 15 linear feet before waste because 180 divided by 12 equals 15.
How do I use reverse mode?
Use linear feet to square feet when you already know how much material you have. Enter the length, actual width, and waste to see the area it can cover.
Why does nominal size make the order short?
Nominal size is a name, not the covered width. Using 6 inches for a 5.5 inch board overstates coverage by about 9%, so the calculator uses the actual width you enter.
Should I round to board count or exact feet?
Buy in the lengths your supplier sells. If you need 120 linear feet and boards are 8 ft long, order at least 15 boards before allowing for bad boards or layout waste.
What waste factor should I use?
Use 5 to 10% for straight runs, 10 to 15% for trim with miters, and 15 to 20% for diagonal flooring, herringbone, closets, or heavy pattern matching.
Can I use this for fencing?
Yes. Calculate the fence face area, enter the actual picket width, and use the result as linear feet of pickets. For posts and rails, use the fence calculator.
When do I need board feet instead?
Use linear feet for length orders. Use board feet when buying hardwood or rough lumber by volume. Convert with the board foot calculator.
Conversion Mistakes That Cost You Money
Using the nominal board name
A nominal 1x6 is commonly 5.5 inches wide. Entering 6 inches makes the order look smaller than it is and can leave a project short.
Ignoring exposed coverage width
Lap siding, tongue-and-groove boards, and some flooring profiles overlap. Use exposed face width, not the full physical board width.
Mixing inches and feet in the formula
Width must become feet before dividing. The calculator handles this, but hand math should use 5.5 inches as 0.458 feet.
Ordering exact linear feet
Suppliers sell boards and rolls in real lengths. Round up to the nearest board, bundle, or roll length after adding waste.
Treating roll goods like boards
Carpet and sheet vinyl are planned around roll width, room direction, and seams. Linear feet from the calculator is a starting order length, not a seam layout.
Square Feet to Linear Feet for Common Materials
Living Room Hardwood Flooring
Enter the room area and the plank coverage width, not the box label headline. A 300 sq ft room with 3.25 inch planks needs about 1,108 LF before waste. Add more waste for diagonal layouts or many closets.
Whole-House Baseboard Replacement
Trim is usually a reverse-mode problem. Measure wall runs, subtract door openings, then add 10 to 15% for miters and bad cuts. Round up to the 8, 12, or 16 ft lengths your supplier stocks.
Bedroom Carpet Installation
Roll goods use roll width, not board width. A 180 sq ft bedroom on a 12 ft roll needs 15 LF before waste, but seam direction and pattern matching can change the order length.
Important Disclaimer
These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.