Getting a quantity

Open Calculate Quantity on any item and you choose one of five sources for its quantity. Choosing the right one is most of the skill in building a bill that survives a drawing revision.

Method	Quantity comes from	Updates itself
Manual	A number you type	No
Field	A take-off measurement	Yes
Item	Another item in this costing	Yes
Calc Sheet	Dimensions you enter, shown as a calculation	Recalculates from the rows
Formula	Other quantities and variables	Yes

This page is the short version

For each method in full — every button in the modal, the wastage and rounding that are applied afterwards, and the six Output options including the three that convert a measurement into units to order — see Fields, items, formulas and calc sheets.

Manual entry

Type the number.

Right for genuine one-offs — a single call-out fee, a lump sum, something you were told over the phone. Wrong for anything measured off a drawing, because nothing will ever update it.

Field

The quantity comes from a take-off field, so it follows every change to the measurement.

Choose Select Field and pick the field, or use Measure on the plan to open Take-Off with this item in mind, measure, and come back with the item already pointed at the field.

This is the method to reach for whenever the quantity is measurable off a drawing. See Take-off fields and the BOQ.

Item

The quantity comes from another item in this costing — its final calculated quantity, after that item’s own wastage and rounding.

Use it when one item’s quantity genuinely is another’s: mesh chairs from the mesh, bedding sand from the slab area, a second coat from the first. Faster than a formula when the relationship is one-to-one, and it keeps following the source if the source is re-measured.

Caution

If the source item is switched off, this item’s quantity silently becomes zero. Worth knowing if you price options by switching items on and off.

Calc Sheet

The calc sheet is the dimension book: a list of dimensions that multiply out, with the working visible.

Use it when the quantity comes from dimensions you have rather than from a drawing you can measure — a schedule of room sizes, a set of figured dimensions on a sketch, something a client has emailed you.

Its value is that the working is visible. Six weeks later, “why is that 86 m²?” has an answer on the screen instead of in your head.

Worked example

Skirting to four rooms, from a room schedule:

Description	Length	Width	Times	Result
Living perimeter	5.4	4.2	2	19.20
Bed 1 perimeter	3.6	3.2	2	13.60
Bed 2 perimeter	3.4	3.0	2	12.80
Hall	6.8	—	2	13.60
Less door openings	0.87	—	−7	−6.09
				53.11 m

The door deduction is the point. It is on the screen, it is explicit, and anyone checking the bill can see it was allowed for.

Formula

The quantity is derived from other quantities. See Formula fields.

Use it when one quantity genuinely follows another — mesh follows slab area, skirting follows wall length, paint follows wall area.

Choosing between them

Work down this list and take the first that applies:

1. Can it be measured off a drawing? Use a field. It will follow every revision.
2. Is it the same as another item’s quantity? Use item.
3. Does it derive from other quantities? Use a formula.
4. Do you have dimensions but no drawing to measure? Use the calc sheet, so the working is recorded.
5. Otherwise, type it — and flag it.

Typed quantities are the ones that go stale

When a drawing is re-issued, fields and formulas move on their own. Typed quantities do not, and nothing flags them. If you must type a quantity for something measurable, put a Flag on the item so you can find it again.

Input Quantity and Quantity

Input Quantity is what the method produced. Quantity is what the item carries after wastage is applied.

Measure 100 m² into a field, set 10% wastage, and the input quantity is 100 while the quantity is 110. The measurement stays honest and the allowance stays visible.