What is a quantity takeoff in construction?
A quantity takeoff is the process of measuring and counting everything shown on the plans and specs (square feet of drywall, linear feet of pipe, number of doors) so an estimator can price the job. Quantities times unit costs become the estimate, and pricing, overhead, and profit come later. On lump sum work, do your own takeoff.
A quantity takeoff turns drawings into numbers. The estimator goes through the plans and specifications and measures every item that will be built or installed: areas, lengths, volumes, and counts. Those quantities, multiplied by labor and material unit costs, become the estimate. If the takeoff is wrong, the price is wrong, no matter how good the unit costs are.
Takeoff and takeoff mean the same thing in most offices. Some estimators use quantity takeoff to stress that the output is quantities only, before any pricing is applied.
How a takeoff works on a real job
Say a drywall contractor is bidding interior partitions for a small clinic. The estimator measures each wall type from the floor plan and wall section details, then applies the heights and layers shown.
| Wall type | Length (LF) | Height (ft) | Faces | Board area (SF) |
|---|---|---|---|---|
| A: single layer each side | 410 | 10 | 2 | 8,200 |
| B: two layers one side (rated) | 120 | 12 | 3 | 4,320 |
| C: shaft wall | 60 | 12 | 1 | 720 |
| Total before waste | 13,240 |
Next comes a waste factor based on the company's own history, then conversion to sheets, studs, track, screws, tape, and mud. Labor hours come from the same quantities using production rates. Doors and openings are usually counted separately so they can be deducted or priced for framing.
Units used in takeoffs
- Count (EA): doors, fixtures, light fixtures, outlets.
- Linear (LF): pipe, conduit, baseboard, curb, wall length.
- Area (SF or SQ): drywall, flooring, roofing, paint.
- Volume (CY): concrete, excavation, fill.
- Weight (tons or lbs): structural steel and rebar.
Common takeoff mistakes
- Wrong scale. A reduced plan set printed at half size, measured at full scale, doubles or halves everything.
- Missing addenda. A revised sheet in addendum 2 changes wall types and nobody updates the count.
- Reading plans, skipping specs. The plans show a wall. The spec says it needs a specific board or extra layer.
- Double counting. Overlapping areas between sheets, especially at match lines.
- No waste or the wrong waste. Waste on a cut-up remodel is not the same as on a big open floor.
- Scope gaps between trades. Who is taking off blocking, firestopping, or access panels? See scope gap.
Manual vs digital takeoff
Manual takeoff with a scale ruler still works for small jobs. Digital takeoff software measures directly on PDF plans, which is faster on large sets and easier to check. Some BIM workflows pull quantities from the model, though the model is only as complete as what the designer modeled. Whatever the method, the estimator still has to read the specs and think about how the work is actually built.
Related terms
Takeoffs feed the bill of materials, unit cost pricing, and the proposal. For the step by step version, read how to do a quantity takeoff. Smart Business Automator carries takeoff quantities and the budget into the project once the job is won, so the field orders against what was estimated.
Frequently asked questions
Who does the quantity takeoff?
Usually the estimator. Large firms may have a dedicated quantity surveyor or takeoff specialist, and many subcontractors do their own takeoffs even when the GC provides quantities.
Should I trust quantities in the bid documents?
On unit price public work, the owner's quantities are often estimates and you are paid on actual quantities. On lump sum work, do your own takeoff; the contract usually puts the quantity risk on you.
How long does a takeoff take?
It depends on plan size, trade, and tools. A one-trade takeoff on a small tenant space might take hours, while a full GC takeoff on a large building can take days.
What is included in a quantity takeoff?
Quantities of every material and work item, organized by trade or cost code. Pricing, overhead, and profit are added later in the estimate.
