Linear Feet CalculatorLinear ↔ Square ↔ Board Feet — plus fence, cabinet, decking, gutter and freight estimators

What is a linear foot?

A linear foot is the simplest measurement in the entire lumber industry: it is one foot — 12 inches — of length, measured along a board or a run, with no regard for width or thickness. When someone asks "what is a linear foot," the shortest correct answer is that it's a foot, counted in a straight line. A 10-foot 2×10 contains 10 linear feet. So does a 10-foot strip of baseboard, a 10-foot gutter section, and a 10-foot fence rail. The unit deliberately ignores everything except length, which is exactly why it's the default language for anything bought and cut by length: trim, fascia, molding, deck boards, fence rails, gutters, pipes, wire, and fabric.

That definition sounds obvious, yet searches for "linear feet definition" and "what is a linear foot" spike every spring, because the unit gets tangled with square feet and board feet. Here is the clean way to define linear feet: linear feet measure length, square feet measure area, board feet measure volume. A linear foot has no thickness and no width — it is a line. A square foot is a patch of surface with no implied shape. A board foot is a block of wood: 144 cubic inches, the equivalent of a 12 × 12 × 1-inch slab. Three units, three questions: how long, how much area, how much wood.

Linear feet vs. square feet vs. board feet — the core difference

Take one ordinary board: a 2×4 that's 8 feet long. It is 8 linear feet of lumber. Using nominal dimensions it is 5.33 board feet of lumber (2 × 4 × 8 ÷ 12). And at the dressed 3.5-inch width it exposes about 2.33 square feet of face. Same physical stick, three honest answers — and none of them converts into another without bringing in the missing dimension. Length to area needs a width; length to volume needs a width and a thickness. That's the whole reason a linear feet calculator exists: the missing dimension has to be an input, not an assumption.

This is also why there is no universal "linear feet to square feet" factor. A 3.5-inch 2×4 face needs 3.43 linear feet to cover one square foot (12 ÷ 3.5), while an 11.25-inch 2×12 face covers the same square foot with just 1.07 linear feet. Widen the board eight inches and you cut the linear footage by two-thirds — the square footage never moved. Any converter that asks for linear feet and square feet without a width is guessing, and on a material order a guess shows up as a second trip to the lumberyard.

Lineal vs. linear — which spelling is correct?

Both are accepted, and both mean the same thing. "Linear" is the standard English adjective and the one used in math, engineering, and on this page. "Lineal" is trade jargon — you'll hear it in cabinet shops, on jobsites, and on some lumberyard tickets, especially in the American South and Midwest. If a quote says "lineal feet of baseboard," read it as linear feet. The same goes for abbreviations: LF, lin. ft., LNFT, and LFT all refer to linear feet, while "l.f." in construction documents means the same unit. Nobody in the trade will be confused by either spelling; pick one and stay consistent through your material list.

How big is 1 linear foot?

One linear foot equals 12 inches, one third of a yard, or 0.3048 meters. Is linear feet the same as feet? For pure length, yes — a linear foot is a foot. The word "linear" does not change the length; it signals that you're counting length only, as opposed to square feet (area) or board feet (volume). When a countertop shop says "$95 per linear foot," they're billing each 12 inches of counter run, typically at a standard 25½-inch depth. When a freight carrier says "12 linear feet," they mean 12 feet of trailer floor. The number stays a foot; the context changes what it's buying.

How to calculate linear feet

Calculating linear footage is addition, not geometry. The formula is: linear feet = length of one piece (ft) × number of pieces. For runs that turn corners, measure each straight segment and add them. For a closed loop like a fence or baseboard, measure the full perimeter. The only place people trip is forgetting a segment — and the second-place finisher is forgetting that linear feet, once calculated, still need a waste allowance before you order.

The linear feet formula

LF = piece length × piece count. Thirty-two studs at 8 feet = 256 linear feet of 2×4. Nineteen 10-foot pieces of casing = 190 linear feet. For perimeters: LF = 2 × (length + width) for a rectangle, or add every side individually for irregular shapes. For coverage in the other direction, the width enters: LF = square feet × 12 ÷ exposed width in inches. That single formula powers the LF ↔ SF tab above and handles siding, decking, and fascia identically — only the width changes.

How to measure linear feet on the jobsite

Work in this order and you'll never come up short: first, sketch the space on paper — one line per run, labeled with its length. Second, measure every straight run wall to wall, including inside and outside corners for baseboard and crown (wrap the corner; don't stop at it). Third, group the list by board size, because 3¼-inch baseboard and 5¼-inch casing are different orders even though both are "trim." Fourth, subtract nothing you'll actually cut around for short pieces but do subtract full-width openings you'll skip — a 3-foot door removes 3 feet of baseboard. Fifth, add a waste allowance: 5% for straight runs, 10% standard, 15% for diagonal or pattern-matched work. Then round up to whole stock lengths — the calculator above does this automatically and shows the spare footage you'll shelve for future patches.

Linear feet conversions: inches, meters, yards, miles

Linear feet to inches: multiply by 12 — 25 linear feet is 300 inches. Linear feet to meters: multiply by 0.3048 — 100 linear feet is 30.48 m. Linear feet to yards: divide by 3 — carpet and fabric still live in yards, so 60 linear feet is 20 linear yards. Linear feet to linear meters is the same ×0.3048; the word "linear" just carries over. And for the two big fixed points: one mile is 5,280 linear feet, and a typical downtown city block — roughly 300 × 260 feet in many U.S. grids — has a perimeter in the neighborhood of 1,100–1,200 linear feet, though blocks vary widely by city. Converting cubic feet to linear feet needs a cross-section: divide the volume by the board's face area in square feet to get run length, which is exactly what the board-foot tables above reverse-engineer.

Converting square feet to linear feet (and back)

This is the conversion behind most siding, decking, and flooring orders. The math runs through one width: SF = LF × exposed width ÷ 12, so LF = SF × 12 ÷ exposed width. The 12 converts feet to inches so both sides share a unit. Everything else is arithmetic — which is why getting the width right is the entire game.

Why you can't convert SF to LF without a width

Square feet describe area; linear feet describe a line of material that covers that area one board-width at a time. Until you say how wide each pass is, the two numbers aren't linked. A 120-square-foot bathroom wall takes 419 linear feet of 1×4 tongue-and-groove at 3.25 inches exposed — but only 214 linear feet of 1×8 at 6.75 inches exposed. Same wall, half the footage, because each board covers twice the strip. Use the exposed (visible) width after overlap, never the nominal sticker width: a 1×6 lap board showing 5.125 inches needs 2.34 LF per square foot, while the nominal 6 inches would understate that to 2.0 LF per square foot and leave you roughly 15% short at the top corner.

Worked examples: 100, 200, and 500 linear feet to square feet

100 linear feet to square feet: at a 5.5-inch exposed deck board, 100 × 5.5 ÷ 12 ≈ 45.8 sq ft. At a 3.5-inch 2×4 face, ≈ 29.2 sq ft. At an 11.25-inch fascia board, ≈ 93.8 sq ft.

200 linear feet to square feet: double every result — 91.7 sq ft of 5.5-inch decking, 58.3 sq ft of 2×4 face, 187.5 sq ft of fascia. 150 linear feet at 5.5 inches is 68.75 sq ft; 300 linear feet is 137.5 sq ft. The pattern is linear in both directions, which is the point: 50 linear feet to square feet at 5.5 inches is 22.9 sq ft, 1,000 linear feet is 458.3 sq ft, and 1,200 square feet to linear feet at the same width is 1,200 × 12 ÷ 5.5 ≈ 2,618 LF. Set the direction toggle once and the calculator runs every one of these instantly.

How many linear feet in a 12×12 room?

A 12×12 room has a perimeter of 48 linear feet (2 × (12 + 12)). For baseboard, subtract the door swing — typically 3 feet — and you're ordering about 45 linear feet, or 5 pieces of 10-foot stock once you add waste. A 10×10 room works the same way: 40 LF of wall perimeter, roughly 37 LF of baseboard after the door. Count closet returns as extra runs, not percentages — a 3-foot closet adds about 9 linear feet (both sides and the back). These same perimeters answer the ceiling-crown question too, since crown follows the same line as baseboard.

Converting board feet to linear feet (and back)

Board feet price the volume; linear feet describe the length you'll actually cut. The bridge is one number: BF per LF = thickness × width ÷ 12. Nominal 2×4: 0.667 BF per LF. Nominal 2×6: 1.0. Nominal 1×4: 0.333. Nominal 1×6: 0.5. Divide any board-foot quote by that factor and you get the linear footage hidden inside it; multiply your cut list by it and you get the board feet your supplier will bill.

Worked example: board feet to linear feet for hardwood trim

Say a hardwood supplier quotes 100 board feet of 1×6 at $7.50 per board foot. On nominal dimensions, 1×6 carries 0.5 BF per LF, so 100 BF ÷ 0.5 = 200 linear feet — twenty 10-foot boards, or thirteen 16-footers. On dressed dimensions (0.75 × 5.5), the same stock carries 0.344 BF per LF, so 100 BF ≈ 291 linear feet. That 45% spread is not an error — it's the difference between nominal and actual pricing basis, and it's why you always confirm which basis a hardwood quote uses before you build a cut list. The LF ↔ BF tab above has a nominal/actual toggle for exactly this reason.

Linear feet for fences

Fence work starts with linear feet because the run — not the area — drives every purchase: posts, rails, pickets, and concrete are all counted against the fence line. For a rectangular yard, fence run = 2 × (length + width). A 100 × 60-foot lot needs 320 linear feet of fence. Walk the line with a tape for irregular lots; every jog and gate return is a straight segment you add to the total.

From fence linear feet to a material list

From the run, everything else is ratios. Rails: multiply the run by rail rows — a 320-foot run on a 2-rail privacy fence needs 640 linear feet of rail stock, on 3-rail split-rail style 960 LF. Posts: divide the run by spacing and add the corner post — 320 ÷ 8 = 40, plus 1 = 41 posts at 8-foot spacing, or 54 posts at 6-foot spacing. Pickets: for picket styles, multiply the run by 12 and divide by picket width plus gap — 5.5-inch pickets with a 3.5-inch gap cover 8 inches each, so 320 feet (3,840 inches) ÷ 8 ≈ 480 pickets. Subtract gate openings from rail and picket counts, keep the posts (gate posts replace line posts), and add 8% waste for straight picket cuts. The Fence tab above runs this chain on your own dimensions; spacing conventions are standard practice, and the rest is arithmetic.

Linear feet for kitchen cabinets

Cabinet pricing still runs on linear feet for runs of stock and semi-custom cabinetry. The convention: measure the length of each cabinet run at the floor, subtract appliances, and quote base and wall runs separately. A 12 × 10 kitchen with an L-shaped layout has runs of about 12 feet and 10 feet; deduct roughly 5 feet for the range, dishwasher, and refrigerator and the base run comes to about 17 linear feet — 34 LF counting a matching wall run. That's squarely inside the normal range: most kitchens land between 15 and 25 linear feet of base run.

How many linear feet of cabinets do I need?

Measure wall to wall along every wall that will hold cabinets, then subtract each appliance's width: 36 inches for a standard range, 33 inches for a French-door fridge, 24 for a dishwasher, 30 for an over-range microwave combo is usually mounted above the range so it doesn't subtract. Choose the layout — single wall, galley, L-shape, or U-shape — because it decides how many runs stack into the total. Wall cabinets usually mirror the base run minus the window wall and range hood; budgeting wall LF equal to base LF is a fair planning number. The Cabinets tab above implements these layout formulas; the appliance deductions and the wall-run mirror are rules of thumb — reference estimate — verify with local suppliers before you sign a cabinet contract.

The 10×10 kitchen benchmark

The cabinet industry's price-comparison benchmark is the "10×10 kitchen," conventionally 20 linear feet — 10 LF of base cabinets plus 10 LF of wall cabinets in the simplest L-shaped layout. When a supplier advertises "$180 per linear foot," a 20-LF benchmark kitchen prices near $3,600 before upgrades. The benchmark exists so quotes from different shops are comparable; your real kitchen will differ because of appliance count, corner treatment, and island additions. Use it for comparison shopping, not for ordering — measure your own runs for that.

Linear feet for decking

Deck boards are sold by the linear foot; the deck itself is planned in square feet; the bridge between them is the board's exposed width — including the drainage gaps you leave between boards. A 5/4×6 board measures 5.5 inches dressed; spaced at 3/16-inch gaps it covers about 5.31 inches of deck per pass. The formula: LF = deck sq ft × 12 ÷ exposed width.

Square feet to linear feet for decking, worked

Take a 12 × 16 deck: 192 square feet. At 5.31 inches exposed, 192 × 12 ÷ 5.31 ≈ 434 linear feet of decking. At 16-foot stock lengths with 10% waste, that's 434 × 1.1 ÷ 16 ≈ 30 boards — call it 480 purchased linear feet, about 46 LF of it landing in offcuts. Skip the gaps and use 5.5 inches and the same deck needs 419 LF — the difference between those two numbers is what a forgotten drainage gap costs: one full bundle of boards. Diagonal layouts add another 5–15% for angled cuts at the perimeter. The Decking tab above runs this with your own area, gap width, stock length, and waste preset, and prices the purchased board feet if you pick a species.

Linear feet for gutters

Gutters are pure linear-foot products — seamless gutter installers bill by the run, and sectional gutter is bought in 10-foot lengths. The only input that matters is which edges carry gutter. On a gable roof, gutter runs along the two eaves only: 2 × house length. On a hip roof, every edge is an eave, so use the full perimeter: 2 × (length + width). A porch or addition with gutter on three sides runs 2 × length + width.

How many linear feet of gutters do I need?

A 40 × 25-foot gable-roof house needs 80 linear feet of gutter — two 40-foot eaves. The same footprint on a hip roof needs 130 linear feet. Plan one downspout roughly every 30 to 40 feet of run (a reference rule of thumb, not a code requirement): that 80-foot gable run wants 3 downspouts, ideally at corners where water carries off the site. Sectional installs on 10-foot stock add 5–10% waste for overlaps and miter cuts; seamless runs are measured on site and waste almost nothing. The Gutters tab above outputs run length, downspout count, and 10-foot pieces from your footprint.

Linear feet for freight and LTL shipping

In freight, "linear feet" means something different than it does in lumber: it's the amount of trailer floor your shipment occupies, and it's how LTL carriers allocate space and price large shipments. Carriers estimate it by floor-loading your pieces across the trailer — a standard 53-foot dry van has roughly 96 to 100 inches of usable interior width. Pieces per row = usable width ÷ piece width; rows = pieces ÷ pieces per row; linear feet = rows × piece length ÷ 12.

How LTL carriers measure linear feet, worked

Six standard 48 × 40-inch pallets: floor(96 ÷ 40) = 2 pallets per row, so 3 rows × 4 feet = 12 linear feet of trailer. Total weight matters too — 6 pallets at 450 lb is 2,700 lb, about 225 lb per linear foot, comfortably under typical density limits — but a shipment stacking 1,200 lb per linear foot will get re-classed or re-rated. Anything over 96 inches tall can't floor-load and rates as over-dimensional. Stacking two pallets vertically halves the floor space, so stackability is worth real money. Every coefficient here — usable width, down-tall limits, weight density — is a reference estimate — verify with local carriers before booking; each carrier's rulesheet wins over any calculator.

Linear feet per acre and other reference numbers

An acre is an area (43,560 square feet), so its linear-foot perimeter depends on shape. A perfect square acre is 208.7 feet on a side, giving about 835 linear feet of boundary — the number you'd fence on a square lot. Real lots are rarely square: a 50-foot-wide acre runs 871 feet deep and needs over 1,800 linear feet of fence. The table below lists square-lot perimeters for common lot sizes; the Acre tab computes any acreage.

Math reference (√43,560 per square acre) — real lots vary with shape; measure the boundary for fencing quotes.

Common mistakes when you calculate linear feet

Using nominal width instead of exposed width. The single most common siding and decking error. Overlap and gaps eat 0.25–0.75 inches per board; on a 5.5-inch board that's 5–14% of your order, missing at the worst possible moment — the last course. Always convert with the width the weather (or the eye) actually sees.

Quoting linear feet without a waste allowance. A cut list that sums to exactly 436 LF assumes zero mistakes, zero damaged ends, and zero short-offs that can't be reused. Real work runs 5–20% waste depending on angles and material grade. The calculator's waste presets mirror this site's framing and decking assumptions.

Comparing per-linear-foot quotes with per-square-foot quotes directly. A $12/LF countertop at 25½-inch depth is about $56 per square foot; a $45 per square foot quote might include the material the LF quote excludes. Convert both to the same basis before you compare — that's what the LF ↔ SF tab is for.

Forgetting corners and returns. Baseboard wraps inside and outside corners; fence rails jog around gates; gutter returns wrap at fascia ends. Measure the wrap, not the wall. And remember freight linear feet is trailer floor, not lumber length — the word is shared, the meaning is not.