Measurement
Linear Feet Calculator
A free linear feet calculator (also searched as a linear foot calculator) that adds up any number of straight runs and converts them to linear feet. Enter feet, inches, yards, or meters, convert square feet to linear feet, add a waste factor for cuts, and get an instant total — for trim, fencing, decking, flooring, moulding, and more.
Calculator
Linear feet calculator
This linear feet calculator (also searched as a linear foot calculator) adds up any number of straight runs and converts feet, inches, yards, meters, centimeters, and millimeters into linear feet. Add a waste factor for cuts and trims, and enter a board width to also get a square footage estimate — handy for trim, fencing, decking, flooring, and moulding.
Runs to measure
Extra for cuts and waste. 0% = exact.
Adds a square footage estimate.
Converter
Square feet to linear feet calculator
Going the other way? If you know the area and the width of your material, this square feet to linear feet calculator divides the square footage by the width in feet to give the linear feet you need. It is the same math as converting square feet to linear feet by hand — say, for decking, flooring planks, or siding where material is sold by length but you measured the area.
Formula
Linear feet = area (sq ft) ÷ width (ft)
Convert the width from inches to feet first: width ÷ 12. Some people write this as sq ft to linear ft.
Worked examples
Converting square feet to linear feet by hand, step by step.
100 sq ft of 6 in wide material
100 ÷ (6 ÷ 12)
200 lf
120 sq ft of 12 in wide material
120 ÷ (12 ÷ 12)
120 lf
50 sq ft of 10 in wide material
50 ÷ (10 ÷ 12)
60 lf
The basics
What is a linear foot?
A linear foot is a measurement of length in a straight line — it is simply one foot (12 inches) measured along one direction. Width and thickness play no part. Two boards can have the same linear footage but a very different area or volume, because a linear foot only counts length.
Linear feet are the standard way to buy and price anything sold by length rather than area or volume: baseboards, crown moulding, door and window trim, fencing, decking boards, pipe, wire, countertop edges, and fabric. If a supplier quotes a price "per linear foot," you only need the total length, not the width.
In one line
Linear feet = total length in feet
12 inches = 1 linear foot. 3 linear feet = 1 yard. 1 linear foot = 0.3048 meters.
Linear foot vs. foot
They are the same length. "Linear" is added to make it clear you are measuring one dimension — length — and not square feet or board feet.
It ignores width and thickness
A 1×4 and a 2×12 that are both 8 ft long are each 8 linear feet — but they are very different amounts of material.
Where it is used
Trim, baseboard, moulding, fencing, decking, flooring strips, countertops, wire, pipe, rope, and fabric are all commonly sold by the linear foot.
Compare
Linear feet vs. square feet vs. board feet
These three units are easy to mix up, and mixing them up is the most common mistake in lumber math. Linear feet measure length, square feet measure area, and board feet measure volume. Here is how each one works and when to use it.
| Unit | Measures | Formula | Common uses | Example |
|---|---|---|---|---|
| Linear foot | Length (1 dimension) | L | Trim, baseboard, fencing, wire, pipe, fabric | An 8 ft board = 8 linear feet |
| Square foot | Area (2 dimensions) | L × W | Flooring, paint, roofing, drywall, tile | 8 ft × 1 ft = 8 square feet |
| Board foot | Volume (3 dimensions) | L(ft) × W(in) × T(in) ÷ 12 | Hardwood, softwood lumber, framing | 8 ft × 6 in × 1 in = 4 board feet |
One board, measured three ways
Take a single board that is 8 ft long, 6 in wide, and 1 in thick:
Linear feet
8 lf
Length only
Square feet
4 sq ft
8 × 0.5 ft
Board feet
4 bf
8 × 6 × 1 ÷ 12
The math
How to calculate linear feet
Calculating linear feet is mostly measuring and adding. There is no width or thickness in the formula, because a linear foot is just one foot of length. The only real work is making sure every measurement is in the same unit before you add them up.
Formula
Linear feet = Σ (length × quantity)
Add up every run, then add a waste percentage before you buy.
To convert square feet to linear feet, divide the area by the width of the material in feet. To convert linear feet to square feet, multiply the linear feet by the width in feet.
- 01
Measure each run in a straight line
Measure every straight section along its length — wall to wall for baseboard, post to post for fencing, end to end for a board. Unlike area, you never multiply two sides together.
- 02
Convert every measurement to feet
If a run is already in feet, keep it. If it is in inches, divide by 12. Yards multiply by 3, meters multiply by 3.28084. The calculator does this conversion for you when you pick a unit.
- 03
Add the runs and apply waste
Add all the runs together for the total linear feet, then add a waste percentage — typically 10% for straight runs, more for many angled cuts. Buy to the total with waste, not the exact measure.
Worked examples
Here is how the math works by hand for a few common jobs, using the same method the calculator applies.
Baseboard for a room
A 14 ft wall and a 12 ft wall, both used twice
14 + 14 + 12 + 12
52 lf
Fence line
Six 8 ft panels
8 × 6
48 lf
Inches to feet
Four runs of 30 in
(30 ÷ 12) × 4
10 lf
Reference
Linear feet conversion chart
One linear foot equals the values below. Use the multiplier to convert linear feet into another unit, or divide to go the other way.
| Unit | 1 linear ft | Factor |
|---|---|---|
| Inches | 12 in | × 12 |
| Feet | 1 ft | × 1 |
| Yards | 0.3333 yd | ÷ 3 |
| Meters | 0.3048 m | × 0.3048 |
| Centimeters | 30.48 cm | × 30.48 |
| Millimeters | 304.8 mm | × 304.8 |
Baseboard & trim
Measure the perimeter of each room, add door and window returns, then add 10% for miters. Trim is almost always sold by the linear foot.
Fencing & railing
Add together every straight fence run and gate section. Posts are usually counted separately from the linear feet of panel or rail.
Decking & flooring
Convert area to linear feet by dividing square footage by the board width in feet — a 6 in board covers 0.5 sq ft per linear foot.
Wire, cable & pipe
Wire, cable, and conduit are quoted per linear foot of run. Measure each run end to end, then add an allowance for routing around joists, corners, and service loops — many installers use roughly 10%, but confirm against local code and the product datasheet.
FAQ
Linear feet questions, answered
How do you calculate linear feet?
Measure each run in a straight line. If your measurement is already in feet, that number is the linear feet. If it is in inches, divide by 12 to convert to feet. Add every run together to get the total, then add a waste percentage for cuts. Width and thickness do not change the linear feet — they only matter when pricing by the square foot or board foot.
What is the difference between a linear foot and a square foot?
A linear foot measures length in one direction — it is a 12-inch straight line. A square foot measures area, which is length multiplied by width (1 ft × 1 ft). A 1 ft wide board that is 10 ft long is 10 linear feet but also 10 square feet; a 6 in wide board that is 10 ft long is still 10 linear feet but only 5 square feet.
What is the difference between a linear foot and a board foot?
A linear foot measures length only. A board foot measures volume: 1 ft × 1 ft × 1 in, or 144 cubic inches. Lumber that is priced by volume (hardwood, framing) uses board feet, while trim, moulding, fencing, and wiring are usually priced and ordered by the linear foot.
How many linear feet are in a 12×12 room?
For baseboard or trim you measure the perimeter, not the area. A 12 ft × 12 ft room has a perimeter of 12 + 12 + 12 + 12 = 48 linear feet. Add extra for doorways, corners, and waste before you buy.
How do I convert square feet to linear feet?
Divide the square footage by the width of the material in feet. For example, 100 sq ft of 6-inch-wide decking: 6 in ÷ 12 = 0.5 ft, so 100 ÷ 0.5 = 200 linear feet. Always convert the width to feet first, then divide.
Is a linear foot the same as a foot?
Yes. A linear foot is simply a foot (12 inches) measured in a straight line. The word 'linear' is used to make clear that you are measuring length only, not area or volume.
How many meters is a linear foot?
One linear foot equals 0.3048 meters, or 30.48 centimeters. To convert linear feet to meters, multiply the linear feet by 0.3048. To go the other way, multiply meters by 3.28084 to get linear feet.
How many linear feet are in an 8 foot board?
An 8 foot board is exactly 8 linear feet, no matter how wide or thick it is. Linear feet only describe length. If the same board is 6 inches wide, it is also 4 square feet (8 × 0.5) or, at 1 inch thick, 4 board feet.
How do you figure out linear feet with a calculator?
Enter each run's length and unit (feet, inches, yards, or meters) and the quantity. The calculator converts every run to feet and adds them. Use extra rows for mixed lengths, then add a waste percentage if you need extra for cuts. Width is optional — fill it in only if you also want square footage.
How many linear feet are in a square foot?
It depends on the material width. Linear feet = 1 ÷ (width in inches ÷ 12). A 12 in board covers 1 sq ft per linear foot, so 1 sq ft = 1 linear foot. A 6 in board covers 0.5 sq ft per linear foot, so 1 sq ft = 2 linear feet. Always convert width to feet first, then divide the area by that width.
How do you convert linear feet to square feet?
Multiply linear feet by the width of the material in feet. Square feet = linear feet × (width in inches ÷ 12). Example: 20 linear feet of 6-inch decking is 20 × 0.5 = 10 sq ft. The calculator does this when you enter a width with your runs.
How do you calculate linear feet for a fence?
Measure each straight run of fence and add them together. For a rectangular yard that is L by W, the perimeter is 2 × (L + W) linear feet. Count gates as part of the run or separately, and count posts by the piece — they are not included in the linear feet of panel or rail. Add a waste allowance for cuts and corners before you buy.