What is the difference between quantity take off and estimate?
A quantity takeoff measures how much work is in the plans: square yards of paving, linear feet of pipe, each manhole. An estimate prices that work by applying labor, equipment, material and subcontract costs, plus overhead and markup, to reach a bid. The takeoff comes first, and the estimate is built on its quantities.
Quantity take off vs estimate side by side
| Aspect | Quantity takeoff | Estimate |
|---|---|---|
| Question it answers | How much work is there? | What will the work cost? |
| Inputs | Plans, specifications, addenda, bid form units | Takeoff quantities, crew rates, material quotes, subcontract prices |
| Output | A quantity per item in SY, LF, EA, CY or TON | A unit price and total per item, and the bid total |
| Typical document | Quantity list or pay-item schedule | Bid form, proposal or cost breakdown |
| Changes when | Drawings, specifications or addenda change | Quantities, prices or production assumptions change |
How the quantity takeoff feeds the estimate
Each estimate line multiplies a quantity by a unit cost. If the paving quantity is wrong, every cost built on it is wrong in the same proportion, however carefully the unit price was built. That is why quantities are checked against the scope before pricing starts.
On a unit-price bid, the bid form lists each item with an estimated quantity, and payment follows the quantity measured in the field. Contractors often check those estimated quantities with their own takeoff before pricing, since the work they build and order follows the real quantity.
Where quantity takeoff ends and estimating begins
The dividing line is the unit cost. Converting 37,650 SF of paving into 682.41 tons of 3-inch asphalt with a density is still takeoff, because the result is a quantity. Choosing the crew, the production rate and the delivered price for those tons is estimating. One person often does both, but keeping the steps separate makes each one easier to check.
Allowances sit on the same line. The net measured quantity is takeoff; an allowance added so enough material is ordered is a decision the estimate records, with its basis.
Quantity takeoff by pay item in Zip Takeoff
Zip Takeoff is built around the quantity side. Measurements go into conditions, and bid items attached to a condition turn one measured area or length into several pay-item quantities, such as SY of milling and TON of surface course from the same footprint. The Item Library also holds a unit price for each item, and the Estimate page shows each pay item's quantity, unit price and extension, so you can price there or export the quantities to your estimating spreadsheet as XLSX.