Linear Foot Calculator
Enter each piece's length in feet and inches (either field alone works) and the total linear feet updates as you type. Add a price per linear foot to estimate what the material will cost.
| Feet | Inches | Qty | $/ln ft | Ln ft |
|---|
Feet and inches each work on their own, or combine them in the same row: 3 ft 6 in and 42 in give the same answer. Price is optional.
How to calculate linear feet
A linear foot is just an ordinary foot of length, measured in a straight line along the material. It excludes width and thickness entirely. To find your total:
Measure each run and convert any inches to feet, then add everything up. If a measurement is in inches, divide by 12:
What is a linear foot?
Stores price material by the linear foot when only its length varies: the profile is fixed and you buy as much length as you need. Baseboard and crown molding, countertops, gutters, fencing, cable and pipe, deck boards, and shelf stock are all commonly quoted per linear foot ("lineal foot" means the same thing).
Because a linear foot ignores the cross-section, two materials with the same linear footage can hold sharply different amounts of stuff. Ten linear feet of 1×2 furring and ten linear feet of 2×12 are the same length. That's all a linear foot promises.
Square feet to linear feet
Flooring and decking flip the problem around: you know the area to cover and need to know how many feet of boards to buy. Divide the area by the width of one board, expressed in feet:
| Area to cover (sq ft) | Board width (in) | Linear feet |
|---|---|---|
| — |
Use the board's actual face width: a 5/4×6 deck board is 5.5″ wide. Add 5–10% for waste on straight runs, more for diagonal layouts.
Common board widths, and the linear feet needed per 100 square feet of coverage:
| Board | Actual width | Ln ft per 100 sq ft |
|---|---|---|
| 1 × 4 | 3.5″ | 343 |
| 1 × 6 / deck board | 5.5″ | 218 |
| 1 × 8 | 7.25″ | 166 |
| 1 × 10 | 9.25″ | 130 |
| 1 × 12 | 11.25″ | 107 |
Linear feet, square feet, board feet
The three units answer different questions, and mixing them up is the classic estimating mistake:
| Unit | Measures | Typical materials |
|---|---|---|
| Linear foot | Length only | Trim, countertops, fencing, gutters, cable |
| Square foot | Area (length × width) | Flooring, drywall, paint, roofing |
| Board foot | Volume (thickness × width × length) | Hardwood lumber |
If you're pricing hardwood by volume instead, use the board foot calculator.
Frequently asked questions
How do I convert inches to linear feet?
Divide by 12. So 30″ is 30 ÷ 12 = 2.5 linear feet. The calculator's inches column does this for you: you can even leave the feet column empty and work entirely in inches.
Is a linear foot the same as a regular foot?
Yes, a linear foot is exactly 12 inches. The word "linear" just emphasizes that you're measuring length in a straight line and ignoring width. "Lineal foot" is the same unit.
How many linear feet do I need for my room's baseboard?
Add up the length of every wall and subtract door openings, then add about 10% for waste and miscuts. A 12′ × 10′ room with one 3′ doorway needs (12 + 12 + 10 + 10 − 3) × 1.1 ≈ 45 linear feet.
What's the difference between a linear foot and a square foot?
A linear foot measures length; a square foot measures area. To go from one to the other you need a width: multiply linear feet by width (in feet) to get square feet, or divide square feet by width to get linear feet.
What's the difference between a linear foot and a board foot?
A board foot measures volume: thickness × width × length, so it depends on the board's cross-section. A linear foot is length alone. Hardwood dealers sell by the board foot; home centers usually price trim and dimensional lumber by the piece or the linear foot.