Linear Feet to Square Feet Calculator

Convert a length of boards, panels or roll material into covered area using its effective width. You can also work backward from an area to the continuous length required.

What would you like to find?

Area units

Effective covering widthinUse the width one piece actually covers. Nominal width, overlaps and gaps may require a different value.

Width units

Length per pieceftFor one continuous roll or the already-totaled linear length, leave the quantity at 1.

Length units

Number of equal-length piecespiecesUsed only when finding area. Different lengths or widths should be calculated in separate groups.

Target areaft²Used only when finding required length. This is the net area before allowance.

Extra material allowance%Adds purchasing area and continuous length without changing net coverage. It is not a cutting-layout optimizer.

Calculation results

Estimated material

—

How to use this calculator

Choose the direction

Find area from an existing material length, or find the continuous length needed to cover a target area.

Enter the effective width

Length cannot become area without a width. Use consistent coverage dimensions, allowing for any overlap according to the product’s specification.

Choose each unit explicitly

Length and width can use different units. The calculator converts them before multiplying or dividing; changing a unit selector converts the value already entered.

Keep net coverage separate

The main answer is net area or net length. The breakdown adds your optional purchasing allowance separately, without rounding continuous lengths up to whole feet.

Formula and worked example

Forward: area (ft²) = length (ft) × width (in) ÷ 12 × equal-piece quantity
Reverse: length (ft) = target area (ft²) ÷ [width (in) ÷ 12]
Material with allowance = net quantity × (1 + allowance ÷ 100)
1 ft = 0.3048 m; 1 in = 0.0254 m; 1 ft² = 0.09290304 m²

A 100-linear-foot length with an effective width of 6 inches covers 100 × (6 ÷ 12) = 50 ft². A 10% allowance corresponds to 110 linear feet and 55 ft² of material. In reverse mode, covering 100 ft² at the same width needs 200 linear feet before allowance, or 220 linear feet with 10% extra.

Area covered by 100 linear feet

One continuous length or one piece; no overlaps, gaps or allowance beyond the effective width entered. These are geometric examples, not nominal lumber sizes.
Effective width	Width in feet	Net covered area
3 in	0.25 ft	25 ft²
5.5 in	0.458333… ft	45.8333… ft²
6 in	0.5 ft	50 ft²
12 in	1 ft	100 ft²

Frequently asked questions

How many square feet are in one linear foot?

It depends on width. One linear foot of 6-inch-wide material covers 0.5 ft²; at 12 inches wide it covers 1 ft². Length and area are different dimensions, so there is no width-free conversion.

Should I use nominal board width?

Use the actual effective covering width for your product and layout. A nominal description alone does not establish exact dimensions. If boards overlap, use the exposed coverage specified for the assembly.

Does a gap between boards count as material area?

No. With actual board width, the answer is the material’s covered area and excludes open gaps. If you instead need an assembly footprint, use the appropriate module width and account for edge conditions separately.

Can I enter several pieces or rolls?

Yes, in forward mode when all pieces have the same entered length and effective width. For mixed sizes, calculate each group and add its area. Do not multiply again if your length already totals every piece.

Will reverse mode tell me exactly what lengths to buy?

It gives a continuous length estimate, plus an optional allowance. Available stock lengths, seams, cuts, kerf, pattern matching and installation layout can increase the purchase quantity. This tool does not produce a cut list.

Methodology and sources

The model assumes rectangular, constant-width coverage. It does not estimate board feet, volume, weight or structural capacity. Results keep fractional lengths rather than rounding them to stock units. For irregular shapes, mixed widths, waste-sensitive cutting or patterned rolls, use a layout-specific takeoff.

NIST Handbook 44 — measurement tables — Source of the exact customary/metric length and area unit definitions. The calculations use rectangle area and its algebraic inverse.

Sources checked September 1, 2026. Referenced organizations do not endorse Efficienco. Calculations retain full precision until display. Continuous lengths and areas are not rounded up to stock units.