Estimating and bidding

How to do a quantity takeoff

A quantity takeoff is the measured list of everything a job needs, pulled from the drawings and specs and organized by cost code. Do it in a fixed order, record every assumption, add waste separately, and have someone check the biggest items.

Two construction professionals review paper plans beside a tablet at a jobsite workbench.
Plan reviews connect field conditions, drawings, and the next decisions on a job. AI-generated illustration.

To do a quantity takeoff, gather the full drawing set and specs, confirm the scale on every sheet, and set up your takeoff by cost code in the same structure as your estimate. Then measure each item in the unit you price it in: counts (each), lengths (linear feet), areas (square feet), and volumes (cubic yards). Work sheet by sheet and trade by trade, mark what you have measured so nothing is counted twice, write down every assumption, and keep waste as a separate factor rather than burying it in the quantity. Finish with a check of the largest items by a second person. The output is a list of quantities the estimate turns into dollars.

A quantity takeoff (often just called a takeoff) is the foundation of every estimate. If the quantities are wrong, perfect pricing still produces a wrong number.

Before you start measuring

Get the complete, current set

Confirm you have every sheet listed on the drawing index, every addendum, and the specifications. Takeoffs done on an outdated set are a classic source of bid errors. Note the issue date of the set you measured.

Read the specs for the trades you are taking off

Specs often add scope the drawings do not show: testing, mock-ups, extra stock, specific products that change waste or labor. Read the sections for your work before measuring.

Verify scale

Check the printed scale against a known dimension on each sheet, especially on PDFs, which may have been resized. Details and enlarged plans often use different scales than the floor plan.

Set up by cost code

Organize the takeoff the way you price and track costs. A concrete contractor might use footings, foundation walls, slab on grade, and flatwork. A GC might follow a MasterFormat-style structure. Matching the takeoff to your cost codes makes pricing and later job costing straightforward.

How to do the takeoff, step by step

  1. Start with the big picture. Measure gross building areas and perimeters first. Many items scale from them, and they give you a check on later numbers.
  2. Work one trade or system at a time. Finish all slabs before moving to walls. Switching back and forth causes misses.
  3. Use the right unit for each item. Count doors, fixtures, and devices. Measure walls, piping, and trim in linear feet. Measure floors, roofing, and drywall in square feet. Measure concrete and excavation in cubic yards.
  4. Mark as you go. Highlight or color each measured item on the plan, by system. Anything unmarked at the end is a miss or not your scope.
  5. Record assumptions next to the quantity. "Assumed 4 inch slab per detail 3/S-201, no thickened edges shown at storefront" protects you and tells the PM what was priced.
  6. Deduct openings when it matters. Large openings in drywall or masonry should come out. Small ones often do not, depending on your pricing method. Be consistent.
  7. Apply waste as a separate factor. Keep the measured quantity clean and add waste by material type. That way you can compare to actual use after the job.
  8. Cross-check totals. Does the drywall area make sense for the wall length and height? Does the slab volume match area times thickness? Simple sanity checks catch big errors.
  9. Have someone else check the top items. The five or ten biggest dollar items deserve a second look.

Worked example: slab and interior partitions

Say an estimator takes off part of a small commercial building: a 60 by 40 foot slab on grade at 4 inches, and 180 linear feet of interior partitions at 9 feet high with drywall on both sides and 10 doors at 3 by 7 feet.

Example takeoff calculations
ItemCalculationMeasured quantityWith waste
Slab concrete60 ft x 40 ft x 0.333 ft = 800 cu ft, divided by 2729.6 CY31.1 CY at 5%
Wall framing180 LF of partitions180 LFStuds priced per LF from history
Drywall gross180 LF x 9 ft x 2 sides3,240 SF
Less door openings10 doors x 21 SF x 2 sides(420 SF)
Drywall net3,240 minus 4202,820 SF3,102 SF at 10%
Drywall sheets3,102 SF divided by 48 SF per 4x12 sheet65 sheets
DoorsCount from door schedule10 each

Note the habits: the slab thickness assumption comes from a specific detail, waste is shown separately, and openings are deducted consistently. The concrete figure would also get checked against thickened edges and any slab depressions shown on the structural sheets, which are easy to miss.

How takeoffs differ by trade

The steps are the same, but each trade has its traps.

  • Concrete: thickened edges, depressions, and footings shown only on sections. Rebar is often taken off by weight from the structural schedules.
  • Framing and drywall: wall types change height and layers. Check the partition schedule, not just the plan lines, and watch for walls that go to deck instead of to the ceiling.
  • MEP: fixtures and devices are counted from plans and schedules, while pipe, duct, and conduit runs are measured. Fittings are usually priced as a factor or counted on larger jobs.
  • Roofing: measure the actual sloped area, not the footprint, and count penetrations, curbs, and flashing lengths.
  • Sitework: cut and fill volumes depend on existing and finished grades and soil swell. Read the geotechnical report.

Knowing the traps for your trade is most of what separates a reliable takeoff from a fast one.

Manual vs digital takeoff

Paper takeoffs with a scale ruler and highlighters still work for small jobs. Most estimators now use PDF-based digital takeoff software, which measures from the drawing once the scale is calibrated and links quantities to estimate line items. The process above does not change. Digital tools make measuring faster, but a wrong scale or a missed sheet produces wrong numbers just as fast. Some newer tools use automated recognition to count symbols or measure areas; treat those results as a draft to verify. See AI for construction estimating: what works today.

Mistakes to avoid

  1. Measuring from an old set. Always confirm addenda and revision dates.
  2. Wrong scale. One resized PDF can throw off every quantity on the sheet.
  3. Double counting. Items shown on both the plan and an enlarged plan get measured twice unless you mark as you go.
  4. Hiding waste in the quantity. You lose the ability to compare estimated to actual use.
  5. Ignoring specs. Testing, attic stock, and specific products change quantities and prices.
  6. No assumptions recorded. If the PM cannot tell what you measured, they cannot manage it.
  7. Skipping the check. A misplaced decimal on the largest line item can sink a bid.

Templates, terms, and related guides

A construction estimate template gives the quantities a place to be priced. Related terms: bill of materials, unit cost, and specifications. Read how to read construction plans for estimating for drawing basics, then how to estimate a construction project to turn quantities into a price. Over time, compare takeoff quantities to what was actually used and store the results in your estimating database.

Smart Business Automator carries estimate quantities and cost codes into the job budget, so actual material use can be compared to the takeoff during the job. See estimate to project handoff automation.

Frequently asked questions

What is the difference between a takeoff and an estimate?

The takeoff is the measured quantities of materials and work. The estimate applies prices, labor, equipment, overhead, and profit to those quantities to arrive at a cost and a bid price.

What units are used in a quantity takeoff?

Each (counts), linear feet, square feet, and cubic yards are the most common. Some items use tons, gallons, or other units. Use the unit you price the item in.

How much waste should I add to a takeoff?

It depends on the material, layout, and your crews. Track actual use against measured quantities on completed jobs and set your waste factors from that history rather than a generic number.

Should I deduct door and window openings?

Usually for large openings in drywall, masonry, and siding. Many estimators skip small openings. The key is to be consistent and to note your method in the takeoff.

Is digital takeoff software worth it?

For contractors who bid often from PDF drawings, it typically saves time and keeps quantities linked to the estimate. Small contractors with a few bids a month can still do accurate takeoffs by hand.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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