What is my linear foot total?

How it works

The calculator finds a running length in one of three ways, then adds the extra for waste:

• Square feet: length = area ÷ (board width + gap). 144 ft² of 6 in boards is 144 × 144 in² ÷ 6 in = 3,456 in = 288 ft.
• Pieces: length = number of pieces × length of each piece.
• Perimeter: length = 2 × (length + width) of a rectangle.
• Linear feet = length × (1 + waste ÷ 100), also shown in metres (× 0.3048) and yards (÷ 3).
• Boards to buy (when you type a board length) = linear length ÷ board length, rounded up to a whole board.
• Cost (when you type a price) = linear feet × price per linear foot.

Exact arithmetic. Each size is read as the exact decimal you typed, in the unit you typed it in (12 ft 6 in is exactly 150 in). When you type in a unit, the page stores the size in metres and reads it back as the decimal with the fewest significant digits, in one of the box's units, that gives the same stored number (a feet-and-inches pair counts by its value in inches; on a tie the first unit in the menu wins). When no decimal of up to 17 significant digits in those units gives the stored number (a value that was not typed on the page), the stored number's own shortest decimal, in metres or square metres, is used. Every step is an exact fraction, so 288 ft of 12 ft boards is exactly 24 boards.

Output format. Linear feet, metres and yards show with at most 2 decimals, rounded half up from the exact value, with trailing zeros left off. Boards is a whole number, rounded up; the cost is in dollars and cents. In Metric the answer leads with metres.

There is no answer, with a message, when the board length is so short that the number of boards is beyond the largest 64-bit number.

Assumptions

• Waste: 10% by default (TimberTech: at least 10% to 15%; Trex: about 5%); from 0% to 100%.
• Board width 5.5 in and gap 3/16 in (0.1875 in) by default: the actual width of a nominal 6 in deck board (Trex, TimberTech) and TimberTech’s composite decking gap. The board width is at least 1 mm and at most 10 m; the gap from 0 to 10 m.
• Lengths are more than 0 and at most 10,000 m; an area at most 1,000,000 m²; 1 to 1,000,000 pieces.
• Boards run the full length; joins and patterns are covered by the waste share.

Worked examples by hand

A 200 ft² deck, 5.5 in boards, 3/16 in gaps, 10% extra. Each board covers 5.5 + 0.1875 = 5.6875 in. 200 × 144 ÷ 5.6875 = 5,063.74 in = 421.98 ft; × 1.1 = 464.18 linear feet = 141.48 m.

144 ft² of 6 in boards, no gap, no extra, 12 ft boards at $2.50 a foot. 144 × 144 ÷ 6 = 3,456 in = 288 ft = 96 yd. 288 ÷ 12 = 24 boards. 288 × $2.50 = $720.

12 pieces of 8 ft. 12 × 8 = 96 ft = 96 × 0.3048 = 29.26 m.

Fencing around a 20 × 12 ft yard, 5% extra, 8 ft boards. 2 × (20 + 12) = 64 ft; × 1.05 = 67.2 ft. 67.2 ÷ 8 = 8.4, so 9 boards.