Linear Feet to Square Feet Calculator
Total Area
Total Price
Visual Diagram
InteractiveMaterial Width Calculator
Quick ConvertHow to Calculate Square Feet from Linear Feet
Linear feet measure length in a straight line — one dimension only. Square feet measure area — two dimensions. To convert linear feet to square feet, you need the material's width. The formula is simple: multiply the linear footage by the width. This is handy for flooring rolls and trim — pair it with our flooring calculator, estimate spend with the price per square foot calculator, or measure a room using the main square footage calculator.
The Core Formula
Conversion Formula
Key FormulaExample: 20 linear feet of 3-foot-wide carpet = 20 × 3 = 60 sq ft
When Width Is in Inches
Many materials (lumber, trim, decking boards) have widths measured in inches. Divide the inch width by 12 to convert to feet before multiplying. A 6-inch-wide board that is 10 linear feet long covers: 10 × (6/12) = 10 × 0.5 = 5 square feet.
What Is a Linear Foot?
A linear foot is simply 12 inches of length, measured in a straight line. Unlike square feet (which describe area) or board feet (which describe volume), a linear foot has no width or depth — it's purely a length measurement. Materials sold "by the linear foot" are priced based on length alone, regardless of width.
Common Materials: Linear Feet to Square Feet
| Material | Typical Width | 10 Lin Ft = | 50 Lin Ft = |
|---|---|---|---|
| Carpet roll | 12 ft | 120 sq ft | 600 sq ft |
| Vinyl flooring roll | 6 ft | 60 sq ft | 300 sq ft |
| Fence board (6") | 0.5 ft | 5 sq ft | 25 sq ft |
| Deck board (5.5") | 0.458 ft | 4.58 sq ft | 22.92 sq ft |
| Baseboard trim (3.5") | 0.292 ft | 2.92 sq ft | 14.58 sq ft |
| Plywood strip (4 ft) | 4 ft | 40 sq ft | 200 sq ft |
| Countertop (25") | 2.083 ft | 20.83 sq ft | 104.17 sq ft |
| Wallpaper roll | 1.75 ft (21") | 17.50 sq ft | 87.50 sq ft |
How to Use This Table
Find your material, note its width, then multiply by your total linear footage. For materials not listed, measure the width yourself and use the calculator above.
Practical Uses for Linear to Square Feet Conversion
Lumber and Decking
Deck boards, fence pickets, and siding planks are sold by the linear foot. To figure out how many boards cover your deck or fence area: divide the total square footage by each board's square footage (length × width). A 200 sq ft deck using 5.5"-wide boards at 8 ft long needs: 200 ÷ (8 × 0.458) = 55 boards.
Carpet and Vinyl Rolls
Carpet comes in rolls with fixed widths (typically 12 ft or 15 ft). The installer cuts the linear footage needed to cover your room. For a 12 ft × 15 ft room with a 12-ft-wide roll, you need 15 linear feet of carpet = 180 sq ft.
Fencing
Fence materials are priced per linear foot (for rails and posts) or per board. Calculate how many pickets you need: measure the total fence length in linear feet, then divide by each picket's width (usually 3.5" or 5.5") to get the board count.
Countertops and Trim
Countertop slabs and trim molding are measured in linear feet. Multiply by the material width to confirm you have enough square footage coverage. Countertops are typically 25 inches wide (2.08 ft), so 10 linear feet covers about 20.83 sq ft.
Wallpaper
Wallpaper rolls list length in linear feet and width in inches (commonly 21" or 27"). Calculate total coverage per roll: linear feet × width in feet. Compare that against your wall area to determine how many rolls you need.
Converting Square Feet to Linear Feet
The Reverse Formula
If you know the area you need to cover and the material width, divide the square footage by the width in feet. Linear Feet = Square Feet ÷ Width (ft). For example, covering 300 sq ft with 12-ft-wide carpet: 300 ÷ 12 = 25 linear feet needed.
Reverse Formula
InverseAdding Waste Factor
Always add 10–15% extra linear footage for seams, cuts, and pattern matching. For carpet, add at least 10%. For patterned wallpaper, add 15–20% since pattern alignment wastes more material at each seam.
Linear Feet vs. Board Feet vs. Square Feet
Linear Feet
Measures length only — a single straight-line dimension. Used to price fencing, trim, piping, and rolled materials. No width or thickness involved.
Square Feet
Measures area — length × width. Used for flooring, paint coverage, roofing, and property sizing. Two-dimensional.
Board Feet
Measures volume — length × width × thickness. Used for rough lumber pricing. One board foot equals a piece that is 1 foot long, 1 foot wide, and 1 inch thick (144 cubic inches). A 2×4 at 8 feet long = (2 × 4 × 96) ÷ 144 = 5.33 board feet.
Which Measurement Do I Need?
Use linear feet when buying materials sold by length (rope, pipe, trim). Use square feet when covering surfaces (floors, walls, roofs). Use board feet when buying hardwood lumber priced by volume.
Industry Examples
Real-WorldFlooring
Decking
Carpet
Fabric
Fence Boards
Baseboards
Vinyl
Visual Examples
Interactive Examples
Click a material type to auto-fill the calculator above with real-world values.
Why Can't Linear Feet Convert Directly?
Linear feet measures only length — a single dimension. Square feet measures area — two dimensions. Without knowing the width of your material, converting is impossible. Here's why:
You have 100 linear feet of material
Material is 6 inches wide
100 × 0.5 = 50 sq ft
Common Material Width Chart
Reference| Material | Width |
|---|---|
| Hardwood | 2.25" |
| Vinyl | 6" |
| Laminate | 8" |
| Carpet | 12 ft |
| Turf | 15 ft |
| Fabric | 54 in |
| Fence | 6 in |
| Deck Board | 5.5 in |
Linear Feet vs Square Feet
Linear Feet
Length only
Square Feet
Length × Width
Specialized Square Feet Calculators
Each tool is purpose-built with its own dedicated calculator, visual diagrams, and step-by-step guidance.
Triangle
Find the area of any triangle using base × height or Heron's formula with three side lengths.
Irregular Shape
Break any complex shape into rectangles and triangles. Add sections and sum them automatically.
Inches
Enter measurements in inches and get instant square feet results. Includes a quick-reference conversion table.
From Meters
Convert metric measurements to square feet. Perfect for international real estate and imported materials.
Linear Feet
Convert linear footage to square feet for lumber, carpet, fencing, decking, and rolled materials.
Sq Meters
Convert sq ft to sq m with live dual display. Essential for international real estate and architecture.
Sq Yards
Divide sq ft by 9 to get sq yd. Perfect for carpet ordering, sod purchases, and fabric estimates.
Acres
Convert property area from sq ft to acres. Ideal for land sales, farming, zoning, and lot size comparisons.
Cubic Feet
Add depth to any area to calculate volume. Essential for concrete, mulch, soil, gravel, and pool planning.
House
Add rooms one by one and get your home's total square footage, with a live bar chart breakdown per room.
Room
Measure rectangular or L-shaped rooms for flooring, paint, and renovation budgeting with instant cost estimates.
Wall
Get net wall area for paint, wallpaper, or tile by subtracting doors and windows from the gross surface.
Tile
Enter room size and tile dimensions to calculate tile count, boxes to buy, and total material cost including waste.
Concrete
Get slab area, cubic yards of concrete, bags needed, and pour cost for any project.
Land
Measure any property lot or parcel in sq ft and acres. Supports rectangular, triangular, and irregular shapes.
BTU Calculator
Calculate heating and cooling BTU needs per square foot based on climate zone, ceiling height, and insulation.
Cost
Estimate total project cost from area and price per square foot. Compare scenarios with tax and markup.
Flooring
Find exact flooring material for hardwood, laminate, vinyl, or carpet with waste factor and box count.
Roof
Get true roof surface area using pitch multiplier. Includes roofing squares, shingle bundles, and cost.
Paint Area
Get paintable wall area with door and window deductions. Calculates gallons, coats, and total paint cost.
Estimation
Add multiple areas, apply buffer percentages, and get quick estimates for budgeting any project.
Related Calculators
Explore other free square footage and cost tools:
Frequently Asked Questions
Multiply the linear footage by the material width (in feet). For example, 30 linear feet of 4-foot-wide material = 30 × 4 = 120 square feet.
Yes — both are exactly 12 inches. "Linear" simply clarifies that you're measuring in a straight line (length only), with no width or area involved.
It depends on the carpet roll width. With a 12-ft-wide roll, you need 15 linear feet (the room length). With a 15-ft-wide roll, you need 12 linear feet. Add 10% for waste.
Multiply each board's length (in feet) by its width (in feet). A 6-ft-tall, 5.5-inch-wide picket = 6 × 0.458 = 2.75 sq ft per board. Divide your total fence area by this number to get the board count.
Divide the area by the board width in feet. For 5.5-inch (0.458 ft) wide boards: 200 ÷ 0.458 = 437 linear feet of decking. Add 10% for waste: approximately 481 linear feet.
Linear feet measures length only (1D). Board feet measures volume (3D) — length × width × thickness. One board foot = 144 cubic inches. They're used for different purchasing purposes.
A standard American wallpaper roll is about 27 inches wide and 27 feet long, covering roughly 60.75 sq ft (27 × 27/12). Subtract about 20% for pattern matching waste, giving you ~48 usable sq ft per roll.
No. You must know the material width to convert between linear and square feet. Without width, the conversion is impossible because linear feet is one-dimensional and square feet is two-dimensional.
Measure the total perimeter of the room (sum of all wall lengths), then subtract the width of each doorway. The result is the linear footage of trim needed. Add 10% for mitered corner cuts and waste.
It depends on the material width. 100 linear feet of a 6-inch-wide board = 50 sq ft. 100 linear feet of 12-ft-wide carpet = 1,200 sq ft. You must know the width to calculate area.
Yes, but you need the material width. The formula is: Square Feet = Linear Feet × Width (in feet). Without width, conversion is impossible because linear feet measures only length.
Measure the linear footage of your flooring planks or rolls, then multiply by the plank/roll width in feet. For example, 80 linear feet of 8-inch (0.667 ft) planks = 80 × 0.667 = 53.3 sq ft of flooring.
Convert 6 inches to feet: 6 ÷ 12 = 0.5 ft. Then multiply: 200 × 0.5 = 100 square feet. That's the total area covered by 200 linear feet of 6-inch-wide boards.
Carpet is sold in rolls with fixed widths (usually 12 ft or 15 ft). Multiply the linear feet by the roll width. For example, 25 linear feet of a 12-ft-wide carpet roll = 25 × 12 = 300 square feet.
The width depends on your material. Common widths: hardwood flooring 2.25–5 inches, vinyl planks 6–8 inches, carpet rolls 12–15 ft, fabric 45–60 inches, fence boards 3.5–5.5 inches, deck boards 5.5 inches.
Because linear feet measures only length (one dimension), while square feet measures area (two dimensions). Without knowing the width, there's no way to calculate area. It's like knowing how long a road is but not how wide — you can't determine its surface area.
Linear feet measure length in a straight line (one dimension), while square feet measure total area (two dimensions). To convert linear feet to square feet, you must multiply the length by the width of the material.
Multiply the linear footage by the material width in feet. If the width is in inches, divide it by 12 first to convert to feet before multiplying (e.g., Linear Feet × (Width in inches ÷ 12)).