Formulas

A formula property computes its value from the row's other properties: the days left until a due date, a label that turns red when something is overdue, or a count of the contacts a row links to. Pages formulas use Notion's Formulas 2.0 language, so a formula you wrote in Notion works here, and Obsidian Bases function names work as alternatives. Formulas are worked out by Dhaga, never by running code you paste in.

Write a formula

Add a Formula property to a database and open it. Type the formula; its result for the first few rows shows as you type, and a mistake shows an error that points at the problem. A formula can be up to 10,000 characters long.

Refer to another property with prop("Name"). A few complete formulas:

// Days until the due date
dateBetween(prop("Due"), today(), "days")

// A label that changes with the status
if(prop("Status") == "Done", "Done", "Open")

// Name a value once, then use it
let(left, dateBetween(prop("Due"), today(), "days"),
  ifs(left < 0, style("Overdue", "b", "red"),
      left == 0, "Due today",
      format(left) + " days left"))

// How many scores in a list are above 7
prop("Scores").filter(current > 7).length()

Can't remember a function? Describe what you want in plain English and the formula writer drafts it for you. It uses AI credits; writing formulas yourself does not.

Operators

Function reference

Logic

Numbers

Text

Regular expressions

Dates

Units for dateAdd, dateSubtract and dateBetween are years, quarters, months, weeks, days, hours, minutes, seconds and milliseconds. Adding a month to 31 January gives the last day of February.

Lists

Lists come from multi-selects, relations, rollups, people properties and split. Inside map, filter and the other list functions, current is the item being looked at and index is its position.

Most functions can also be written as a method on their first argument: prop("Tags").join(", ") is the same as join(prop("Tags"), ", ").

Rows and people

Obsidian Bases names

If you write formulas in Obsidian Bases, its function names work too and mean the same thing as the Notion function they correspond to: average for mean, isEmpty for empty, number for toNumber, matches for test, count for length, and acc and value for accumulator and current. A few functions exist only for Bases formulas, mostly in base views that read from a search: hasTag, hasLink, hasProperty, inFolder, time and relative. A base file imported from an Obsidian vault keeps its formulas.

Limits

A view works out formulas for up to 5,000 rows at a time. Past that, the view shows an error saying the database is too large to compute there, instead of quietly showing partial results. Filter the view to bring it under the limit.