Calculating one column from another: per-row formulas like price times tax

Summing a whole column is one thing; a genuinely common request goes a step further – a column whose value depends on other columns in the same row, such as a total price computed from a unit price and a tax rate. Plain Confluence tables have no concept of a per-row formula at all, so this is normally done by hand and re-typed every time a source number changes.

On Confluence Cloud: the Numerical Expression macro is called CelesteCS Numerical Expression Cloud, and CelesteCS Reporting for Confluence Cloud uses the same Reporting Table Item formula syntax shown below – both approaches work the same way as on Data Center.

Confluence table with unit price and tax rate per item and a Math formula in each row showing the total including tax

One macro per row

The most direct approach is a small Numerical Expression macro in the result column of each row, referencing that row’s own cells:

  • Row 2: Table1.B2 * (1 + Table1.C2)
  • Row 3: Table1.B3 * (1 + Table1.C3)

with B holding the unit price and C the tax rate as a decimal (e.g. 0.2 for 20%). Each macro is independent, so rows can be added, removed or reordered without renumbering anything else – every macro only ever looks at its own row.

Formatting the result

Wrap the formula in FORMAT or TEXT to show it as currency instead of a bare number, for example TEXT(Table1.B2 * (1 + Table1.C2), "$0.00"), which turns 132 into $132.00.

When there are many rows

Placing one macro per row works well for a handful of rows, but does not scale to a table with fifty of them. At that point it is worth building the table with CelesteCS Reporting instead: a single Reporting Table Item formula such as CurrentItem.unitPrice * (1 + CurrentItem.taxRate) is evaluated once per row automatically for however many rows the data provider returns, with no per-row macro copy-pasting at all – see our article on going beyond the Jira Issues macro for the same idea applied to Jira data.

Try it in your own Confluence: CelesteCS Reporting for Confluence on the Atlassian Marketplace – free trial for Cloud and Data Center. This example also uses CelesteCS Math for Confluence.

Math saves you time? A review on the Marketplace helps other teams find it.