What is a quantity takeoff? (And how it's actually done)

By the Give Me The Cost estimating team · Methods reviewed by a senior GTA estimator (25+ years in the field) · Updated July 2026
A quantity takeoff is the measured list of every material a construction project needs, read straight off the drawings. Concrete by volume (m³), rebar and steel by weight (tonnes), formwork by contact area (m²), excavation by volume, and equipment by count. It's the neutral fact base every estimate, bid and budget is built on — quantities only, before a single dollar is applied.

Quantities first, dollars later

A takeoff answers one question: how much of each thing does this building need? It's deliberately separate from pricing. You measure the work — 480 m³ of concrete, 68 tonnes of rebar, 3,200 m² of formwork — and only then does anyone multiply by a rate. Keeping the two apart is what makes a takeoff reusable: the same quantities feed a contractor's bid, an owner's budget, and a lender's review, each applying their own prices.

Every material has its own unit

Part of doing a takeoff right is knowing what unit each trade is measured in — it's not all one number:

TradeMeasured byUnit
ConcreteVolumem³ (or yd³)
Rebar / reinforcingWeighttonnes (kg)
Structural steelWeight (tonnage)tonnes
FormworkContact aream² (or ft²)
ExcavationVolumem³ / yd³ (bank & loose)
Mechanical / electricalCount + lengtheach, plus m of duct/pipe/wire

Mixing units up — pricing rebar by volume, or forming only one face of a wall — is where takeoffs quietly go wrong.

How a takeoff is built, step by step

  1. Read the drawing set — structural (S-series) for the frame, architectural for finishes, mechanical and electrical for systems, plus the schedules.
  2. Measure or count each element — slabs and walls for concrete volume, bars for reinforcing weight, equipment from the schedules.
  3. Convert to the trade's unit and apply the right allowances (rebar laps, formwork both faces, excavation swell).
  4. Total by division so the numbers can be priced, budgeted or bid.

Why it's the most important number on the job

Every dollar downstream rides on the takeoff. Under-measure the concrete and the bid is short before anyone touches a price. Miss the second face of the formwork and the forming budget is halved. The takeoff is the foundation the whole estimate stands on — which is exactly why it's worth getting exactly right, and why it's the part that eats the most hours by hand.

Doing it faster

Give Me The Cost reads your drawing set and produces the whole-building takeoff — every division, in the right unit, with an Ontario Building Code check — in minutes instead of days. It's honest about where each number is measured exactly versus carried as an allowance, so you know what to verify. It doesn't replace judgment; it removes the hours of measuring so you can spend them checking.

Want your project's real quantities, not guesses?
Upload your drawings and get an actual material takeoff — every division, whole building — with an Ontario Building Code check.
Get my takeoff →   Free calculators

Frequently asked questions

What's the difference between a takeoff and an estimate?
A takeoff is the measured quantity of materials (480 m³ of concrete). An estimate applies prices to those quantities to reach a cost. The takeoff comes first and is price-neutral.

What units is a takeoff measured in?
Each trade has its own: concrete by volume (m³/yd³), rebar and steel by weight (tonnes), formwork by contact area (m²), excavation by volume, and mechanical/electrical by count plus length.

Who does quantity takeoffs?
Quantity surveyors, estimators, and contractors — anyone who needs to know how much material a project requires to bid, budget, or order it.

Can a takeoff be automated?
The measuring can. Tools like Give Me The Cost read the drawings and compute quantities automatically, with the estimator verifying the flagged, allowance-based lines.