What Is a Linear Foot and How to Calculate Linear Feet

What a linear foot is and how to calculate linear feet

A linear foot is 12 inches measured in a straight line. A 10 ft board is 10 linear feet whether it is 2 inches wide or 12, which is why lumber yards price by it. So do trim suppliers, fence builders and countertop shops. The width is already fixed by the product, so only the length changes the bill.

By the How Many Bags team. The definitions follow the lumber trade's own usage, and board widths the American Softwood Lumber Standard. The conversions were checked against worked examples. Last updated on 2 November 2026. How these pages are made.

Length, area and volume are three different feet

A linear foot is length: 12 inches along a line. A square foot is area: a square 12 inches on each side, 144 square inches. A cubic foot is volume: a box 12 inches each way, 1,728 cubic inches. Trim, lumber, pipe, fence, cable, countertops and rolls of anything are sold by the linear foot because the product already has its width and thickness. Flooring, tile, paint and sod are sold by the square foot because they cover an area. Concrete, gravel and mulch are sold by the cubic foot or cubic yard because they fill a space. The word lineal means the same as linear and shows up on lumber invoices.

How to calculate linear feet

Measure each piece from end to end. Write the measurement in feet plus inches, convert the inches by dividing by 12, and add the pieces. Three pieces of 8 ft 6 in and one of 11 ft 3 in come to 25.5 + 11.25 = 36.75 linear feet. For a room, add the lengths of the walls and take out each doorway. For a fence, measure along the fence line post to post. For a countertop, measure along the wall at counter height and follow the corners. Then add about 10 percent for cuts and miters. Round up to the stock lengths the material comes in. A 9 ft wall, for example, needs two 8 ft sticks or one 10 ft stick either way.

Square feet to linear feet, and back

Boards cover area, so the question "how many linear feet for 200 square feet" has no answer until the board width is known. Divide the area by the board's face width in feet. For example, 200 square feet of 5 1/2 inch deck boards is 200 ÷ 0.458 = 436 linear feet. The same area in 11 1/4 inch wide 1x12 is 213 linear feet. Going the other way, multiply linear feet by the width in feet. For example, 300 linear feet of 7 1/4 inch shiplap covers 300 × 0.604 = 181 square feet. Use the face width that actually shows, which for tongue-and-groove is less than the board.

Baseboard is the everyday case, and its linear feet come from the room's perimeter less the doorways:

Room	Wall perimeter	With one 3 ft door	With two doors
10 × 10 ft	40 ft	37 ft	34 ft
10 × 12 ft	44 ft	41 ft	38 ft
12 × 12 ft	48 ft	45 ft	42 ft
12 × 14 ft	52 ft	49 ft	46 ft
14 × 16 ft	60 ft	57 ft	54 ft

Board feet are something else

Hardwood lumber is sold by the board foot, which is volume: a piece 1 inch thick by 12 inches wide by 12 inches long. The formula is thickness in inches times width in inches times length in feet, divided by 12, using the nominal sizes the lumber trade quotes. A 2x6 that is 10 ft long is 10 board feet. A 1x12 of the same length is also 10 board feet. A 4x4 of 10 ft is 13.3 board feet. Framing lumber and trim at a home center are priced by the piece or the linear foot. So board feet only come up at a hardwood dealer or a sawmill.

Pricing by the linear foot

Multiply the linear feet by the price per foot, after adding the waste allowance. 48 feet of baseboard at the store's per-foot price plus 10 percent is 52.8 feet to pay for. Home centers sell it by the piece in 8, 10, 12 and 16 ft lengths, so the real bill is for the sticks that cover it. Three 16 ft and one 8 ft is 56 feet. Countertop shops quote per linear foot of a 25 inch deep counter, the usual depth though not a standard and add for deeper sections. Fence contractors quote per linear foot installed, gates extra. When a quote is per linear foot and another is per square foot, convert one to the other with the width before comparing them.

Questions about linear feet

What is a lineal foot?

The same thing as a linear foot. Lumber yards and invoices often write lineal; the measurement is 12 inches of length either way.

How many linear feet of fence go around a quarter acre?

A quarter acre is 10,890 square feet. As a square it is 104.4 ft on a side, about 418 linear feet around; as a 60 by 181 ft lot it is 482 feet. Measure the real lot lines, take off the gate widths, and divide by the panel length, 6 or 8 ft, to count panels.

How many linear feet of baseboard for a 12 by 14 room?

A 12 by 14 room has 52 feet of wall. Take off each doorway, about 3 ft, so 49 feet with one door and 46 with two. Add an allowance for miters and cuts, 10 percent is the calculator's default, then buy the stock lengths that cover it, four 16 ft sticks for a 54 foot run.

How do I price something sold by the linear foot?

Multiply the price per foot by the linear feet you need after the cut allowance. Then round up to the stock lengths the store sells, because you pay for whole sticks. A quote per square foot converts to per linear foot by multiplying by the material's width in feet.

How many linear feet of countertop are in an L-shaped kitchen?

Measure each run along the wall at counter height and add them. A 10 ft run and an 8 ft run is 18 linear feet; the corner is counted once, in whichever run reaches it. Islands count their own length or perimeter, as the shop specifies.