Linear Feet Calculator
Use either method below: calculate total linear feet from pieces, or convert square feet to linear feet using material width.
Method 1: Pieces to Linear Feet
Method 2: Square Feet to Linear Feet
What Is a Linear Foot?
A linear foot is a simple one-dimensional measurement equal to 12 inches in length. It measures only length, not width or thickness. That makes it perfect for projects like trim, fencing, shelving, baseboards, lumber runs, and rolls of material where you mostly care about how long something is.
People often confuse linear feet with square feet. Square feet measure area (length × width), while linear feet measure straight length only. This calculator helps you use the right measurement quickly.
How to Use This Linear Feet Calculator
Method 1: Add Up Individual Pieces
Use this when you know the size of each piece and how many pieces you need. Great for boards, trim, pipe, conduit, and similar materials.
- Enter feet for one piece.
- Add extra inches if needed.
- Enter quantity.
- Optionally add a waste percentage to cover cuts and errors.
Method 2: Convert Square Feet to Linear Feet
Use this for roll goods or strip materials where you know coverage area and width (in inches), such as flooring underlayment, vinyl, carpet, landscape fabric, or membrane products.
Formula: Linear feet = (Square feet × 12) ÷ Width in inches
Linear Feet Formulas (Quick Reference)
- From pieces: Linear feet = (feet + inches/12) × quantity
- With waste: Total = Base linear feet × (1 + waste%/100)
- From area and width: Linear feet = (square feet × 12) ÷ width in inches
- Room perimeter: Linear feet = 2 × (length + width)
Practical Examples
Example 1: Baseboard Trim
You need 18 pieces of trim, each 7 feet 8 inches long, and want 8% extra for waste.
Piece length in feet = 7 + 8/12 = 7.67 ft. Base total = 7.67 × 18 = 138.06 ft. With waste = 149.10 linear feet.
Example 2: Fencing
If each fence panel run is 8 feet and you need 22 runs, total linear feet is 176 ft. Add extra for gates, overlaps, and mistakes if needed.
Example 3: Roll Material
You need to cover 500 square feet using a 24-inch-wide product.
Linear feet = (500 × 12) ÷ 24 = 250 linear feet.
Common Mistakes to Avoid
- Mixing linear feet and square feet without converting.
- Forgetting to convert inches into feet.
- Skipping waste allowance for cuts, corners, and damaged pieces.
- Using nominal instead of actual material width in conversions.
- Rounding too early; keep decimals until final purchasing step.
When to Add a Waste Factor
A waste factor is usually smart when materials must be cut, matched, or fitted around obstacles. Typical ranges:
- 5%: Straightforward projects with minimal cuts
- 8–10%: Standard remodeling jobs
- 12–15%: Complex layouts, odd angles, or many obstacles
Frequently Asked Questions
How many inches are in a linear foot?
Exactly 12 inches.
Is linear feet the same as running feet?
Yes, in most construction and retail contexts, “running feet” and “linear feet” mean the same thing.
Can I convert linear feet directly to square feet?
Only if you also know width. Square feet = linear feet × width (in feet).
Should I round up my final number?
For purchasing, yes. Round up to the next whole unit (board, roll, or bundle), then include waste so you do not run short mid-project.