What is a quantity takeoff in construction?
Published on 10 July 2026
In short: a quantity takeoff is the process of measuring everything a project is built from, straight off the drawings, and listing it as quantities: so many metres of skirting, so many square metres of plaster, so many doors. It is the measured foundation every price and bill of quantities is built on. The name comes from taking the quantities "off" the drawings.
What a takeoff actually is
Before anyone can price a job, someone has to work out how much of everything there is. A quantity takeoff answers that question. Working from the architect's and engineer's drawings, an estimator or quantity surveyor measures each element of the works and records it as a quantity against a clear description. The result is a structured list of measured items, ready to be priced.
A takeoff is quantities only. It does not, on its own, tell you what the job costs. That comes next, when rates for labour, materials and plant are applied to those quantities to build an estimate.
The four things you measure
Almost everything on a drawing is measured in one of four ways, and the unit follows from the method:
- Length (m) - skirting, pipework, kerbs, coving: anything you follow along a line.
- Area (m2) - flooring, plaster, roofing, painting: anything that covers a surface.
- Volume (m3) - concrete, excavation, hardcore: anything measured by the amount of space it fills.
- Count (nr) - doors, windows, sockets, sanitaryware: anything you tally one by one.
UK work is measured in metric units throughout. Getting the method right for each item is what keeps the takeoff consistent and the bill readable.
Net, gross and ordered quantities
It is worth knowing three related numbers. The net quantity is the exact measurement off the drawing. The gross quantity adds a realistic allowance for waste, offcuts and handling losses. The ordered quantity is what you actually buy, often rounded up to whole packs, sheets or loads. A takeoff usually records the net measure, and waste is added when the item is priced or ordered.
Takeoff, estimate, bill of quantities
These three get used loosely, but they are different stages. The takeoff produces the quantities. The estimate applies rates to those quantities to reach a cost. The bill of quantities is the formal document, often measured to NRM2, that sets those items out so every contractor prices the same scope on the same basis.
Why the takeoff matters so much
Every number downstream sits on top of the takeoff. If a quantity is wrong, the price is wrong, the order is wrong, and the margin quietly disappears. Getting the measure right is the single highest-leverage thing an estimator does, which is why so much care, and increasingly so much software, goes into it.
Manual and digital takeoff
Traditionally a takeoff meant a scale rule, a printed drawing and a spreadsheet. Today most estimators measure on the PDF instead: you set the scale once, then click along lengths, around areas and on counts, and the software totals as you go. It is faster, it leaves an audit trail on the drawing, and it removes the arithmetic slips that come with measuring by hand. See digital vs manual takeoff for the trade-offs.
How Kestrel™ does it
Kestrel is a takeoff tool built by a working UK estimating firm. You open the drawing, set the scale, and measure lengths, areas and counts straight on the PDF. Kestrel exports the result as an NRM2 Bill of Quantities in Excel, with quantities, codes, descriptions and live formulas, so you add your rates and the totals update. It runs on Windows, with a 14-day free trial. See the FAQ for how it works, or download Kestrel to try it on a real drawing.