Formulas and parameters
Write quantity formulas with measurement tokens, waste factors, and math operators — and understand how parameters keep your budget in sync with the plan.
A parameter is a named value — usually a plan measurement — that you reference inside a quantity formula. Formulas let a line compute its own quantity instead of you retyping numbers.
Anatomy of a formula
A formula is plain math with measurement tokens mixed in:
{Wall Area}— a token, shown as a colored pill, that pulls in a measurement.* 1.1— multiply by a 10% waste factor.( … ) / 27— group and convert (cubic feet to cubic yards).
So {Slab Area} * {Depth} / 27 reads as: slab area in square feet times depth in feet, converted to cubic yards.
Write a formula
- Double-click a line's Quantity Formula cell (a single click only selects it).
- Type or pick a measurement to insert it as a token.
- Add operators and numbers:
+,-,*,/, and parentheses all work. - Press Enter to commit, or Tab to move to the next field.
- Click Save changes to persist the budget's pending edits.
To round the result, open Functions in the formula picker and choose Round up, Round down, Nearest whole number, or Decimal places. The function wraps your entire formula. In an empty cell, enter the value or variable inside the parentheses; Decimal places starts with two decimal places, which you can change.
Note
Note
You can also double-click a group's Quantity Formula cell to choose a measurement or project parameter. A group can reference a parent assembly's quantity, but not its own quantity or a child or sibling group's quantity.
Manage project parameters
- On the budget toolbar, click Parameters.
- In Project, click Add Parameter, enter a name, and choose Value or Formula. Set its value or expression, format, and unit.
- Click Apply to put the edits into the budget's pending changes. Then save the budget to keep them. Undo and discard also include applied parameter edits.
- Use Takeoffs to inspect measured values; edit those values on the plans. The eye opens the measured page in a new tab.
- Use Assemblies & Rates to find existing assembly quantities and organization rates to reference in formulas.
Don’t see this?
Common patterns
- Waste factor —
{Roof Area} * 1.15for 15% overage. - Unit conversion —
{Trench Volume} / 27from cubic feet to cubic yards. - Coverage —
{Wall Area} / 350for gallons of paint at 350 ft² per gallon. - Stacking —
({Floor 1 Area} + {Floor 2 Area}) * 1.05.
Unit Cost and Unit Price formulas
Quantity isn't the only field a formula can drive — Unit Cost and Unit Price can compute themselves too:
- Unit Cost Formula — computes Unit Cost from org rates and takeoff variables, addressed by name; it can also reference
{Quantity}. Setting one overrides the typed Unit Cost. - Unit Price Formula — sets Unit Price directly, for work quoted as a price rather than cost plus markup (for example
1.25for $1.25/SF final wax). It can reference{Unit Cost}. Setting one makes both Margin % and Markup % calculated instead of editable.
Both columns are hidden by default. Turn them on for a view in View settings (click the eye beside each one); they sit immediately to the left of the number they produce. Double-click either one the same way you open Quantity Formula — type or pick a token, and the line recomputes whenever a referenced value changes.
Note
$72.00/hr — not in the Quantity Formula picker, which offers measurements, project parameters and assembly quantities.Note
Why parameters beat typed numbers
A typed quantity is a snapshot — it goes stale the moment the plan changes. A parameter is a live link: re-measure on the plan, and every formula that references it recomputes, cascading through extended cost, price, and profit. Build the formula once and the math maintains itself.