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Part of: What Is a Takeoff in Construction? How to Do One From Plans

Takeoff Units of Measure: SF, LF, SY, CY and EA Explained

The main construction units of measure are SF (square feet) for area, LF (linear feet) for length, SY (square yards) for some area items, CY (cubic yards) for volume and EA (each) for counted items. Every line on a takeoff needs one of them. A square yard is exactly 9 SF and a cubic yard is exactly 27 cubic feet.

What are the standard takeoff units of measure?

A takeoff measures four kinds of quantity: area, length, volume and count. Each has a short abbreviation that shows up on plans, bid forms and supplier quotes. The table lists the ones you will see most, with the exact conversion for each from NIST Handbook 44, Appendix C, NIST's general tables of units of measurement.

Pick the unit before you measure, not after. If the construction takeoff line says SF and the supplier quotes per SY, convert once on the takeoff sheet so the estimate only ever sees one unit.

What units does an area takeoff use?

An area takeoff is almost always done in square feet (SF). One square foot is 144 square inches. Floor area, wall area, ceiling area and slab area are all measured in SF.

Square yards (SY)

A square yard is 3 feet by 3 feet, so 1 SY = 9 SF exactly. Divide square feet by 9 to get square yards. A 1,440 SF floor is 160 SY. The square feet to square yards converter does it for any number.

Roofing squares (SQ)

Roofing is measured in squares. NIST lists one square (building) as 100 square feet. Divide roof area by 100: a 2,350 SF roof is 23.5 squares. Measure the roof area itself, along the slope, not the footprint of the house below it.

When do you use linear feet (LF)?

Use linear feet for anything you buy or install by length, where width is fixed or does not matter. A linear foot is just a foot of length: 12 inches. Base, crown, casing, fence, curb, gutter and edging all go on the takeoff in LF.

Linear feet and square feet are easy to mix up. The full breakdown, with trade examples, is in square feet vs linear feet.

How do you convert to cubic yards (CY)?

1 CY = 27 cubic feet exactly, because a cubic yard is 3 feet on each side. To get cubic yards for a slab, multiply area in SF by thickness in feet, then divide by 27. One cubic foot is 1,728 cubic inches.

Worked example: a 20 ft by 24 ft slab, 4 inches thick.

1. Area: 20 × 24 = 480 SF
2. Thickness in feet: 4 ÷ 12 = 1/3 ft (about 0.333)
3. Volume: 480 × 1/3 = 160 cubic feet
4. Cubic yards: 160 ÷ 27 = 5.93 CY

The National Ready Mixed Concrete Association's CIP 31, Ordering Ready Mixed Concrete says concrete is sold by volume in cubic yards, and advises ordering about 4% to 10% more than the volume worked out from plan dimensions. On the 5.93 CY slab, that is roughly 6.2 to 6.5 CY. The cubic footage calculator handles the volume math, and concrete takeoff from plans covers measuring slabs and flatwork from a site plan.

What is a board foot (BF)?

A board foot is a volume unit for lumber. Wikipedia's board foot entry defines it as a board one foot long, one foot wide and one inch thick, which is 144 cubic inches.

The working formula is thickness in inches × width in inches × length in feet ÷ 12. A 1 inch by 12 inch board, 8 feet long, is 1 × 12 × 8 ÷ 12 = 8 BF. Lumber you buy by the piece or by the running foot goes on the takeoff in EA or LF instead.

What does EA mean on a takeoff?

EA means each: a plain count. Doors, windows, plumbing fixtures, light fixtures, outlets and hardware sets are all EA items. There is nothing to convert, but there is plenty to miss, so mark each one on the plan as you count it and check the door and window schedules against your total.

How do US units convert to metric?

NIST bases US length units on the international foot, which is exactly 0.3048 meter. From that, every other conversion follows.

• 1 LF = 0.3048 m
• 1 SF = 0.09290304 m²
• 1 SY = 0.83612736 m²
• 1 CY = about 0.765 m³

Convert at the end, not line by line. NIST's own guidance in the same appendix is to keep all the digits and round once, as the last step.

How do you keep units straight in a digital takeoff?

If your measuring tool reports area in SF and length in LF, the conversions above happen in your spreadsheet. MeasureFloorPlan gives floor area in SF, perimeter in LF, gross wall area and ceiling area per room, and counts. Its paint, drywall, flooring and trim presets turn those into gallons, sheets and boxes, and the quantities export to Excel or PDF. See area takeoff software for how it handles a full plan set. If you are still choosing between paper and screen, read manual vs digital takeoff first.

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