Linear Feet vs Square Feet
By the Linear Feet Calculator Team | Reviewed by our construction experts | Updated June 17, 2026
Confused about when to use linear feet vs square feet? This guide explains the key differences, when to use each measurement, and how to convert between them.
Quick Comparison
| Linear Feet (LF) | Square Feet (SF) | |
|---|---|---|
| Measures | Length (1 dimension) | Area (2 dimensions) |
| Formula | Inches / 12 | Length × Width |
| Abbreviation | LF, ln ft | SF, sq ft |
| Used for | Fencing, trim, pipes, cables, gutters | Flooring, painting, tile, roofing, drywall |
| Conversion | LF = SF / Width (ft) | SF = LF × Width (ft) |
When to Use Linear Feet
Use linear feet when only the length matters and width is fixed or irrelevant:
- Fencing: You buy fence by the linear foot — the height is standard
- Trim and baseboards: Sold in linear feet, cut to wall length
- Gutters: Measured along the roofline in linear feet
- Pipes and conduit: Length is what matters for plumbing and electrical
- Countertops: Fabricators price by linear foot of counter run
When to Use Square Feet
Use square feet when you need to cover an area and both length and width vary:
- Flooring: Carpet, tile, hardwood — all sold by square foot
- Painting: Paint coverage is calculated by square feet of wall area
- Drywall: Sold in 4×8 or 4×12 sheets, calculated by square footage
- Roofing: Shingles are sold by the square (100 square feet)
- Landscaping: Sod, mulch, and gravel coverage is in square feet
How to Convert Between Linear Feet and Square Feet
Converting between the two requires knowing the width of the material:
Square Feet = Linear Feet × Width (in feet)
Linear Feet = Square Feet / Width (in feet)
Example
A 6-inch wide deck board is 0.5 feet wide. If you need 100 square feet of decking: 100 / 0.5 = 200 linear feet of deck boards.
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