A rollup can look broken while the setup is technically fine. It stores nothing of its own: it reaches through a relation into another database, reads one property on every linked page, and applies a calculation to the result.

Four links have to hold: the relation, the source property, the calculation, and the connection’s permissions if an integration reads the value. Break one and you get a blank cell or a total that disagrees with the pages you can see. These six checks take about five minutes and usually save you a rebuild. If relations are still new, the Notion database beginner guide covers what they assume.

1. Check the relation on the row, not the column

A rollup shows nothing when a row has no linked page: there is nothing to aggregate, so the cell stays empty instead of showing 0. Column settings can look perfect while half your rows have a blank relation field.

Test it with a second rollup on the same relation, set to Count all, which counts linked pages rather than a property value. Rows that read 0 there have an empty relation; fill the field and the original rollup fills in. Count all is also the one calculation that works when the source property is empty, as described in the relations and rollups documentation.

2. Confirm which database the relation points at

Open the relation property, click Property type, and re-select Relation. Notion then shows which database the property is connected to, and that is also how you repoint a relation that drifted to the wrong table. Worth doing after a copy, which is check 5.

While that menu is open, look at the relation limit. A relation set to 1 page can only hold one linked page, so a Sum over it can never match a customer who bought five items. Wide rollups need No limit.

3. Match the calculation to the source property type

Notion documents Sum, Average, Median, Min, Max and Range for Number properties, and Earliest date, Latest date and Date range for Date properties. Everything else supports the counting and listing options: Show original, Count all, Count values, Count empty and the Percent variants.

Two consequences show up in a broken rollup:

  • If the source holds text, or a formula that returns text, the numeric options have nothing to add and the total sits at 0.
  • If the rollup column has lost its sort menu, that points the same way: rollups can only be sorted when they output a number.

A column that mixes numbers with labels like “TBD” also breaks numeric aggregation, because the text cells are ignored.

4. Inspect the source property, not the rollup

If both check out, the fault is usually on the other side of the link.

  • The source property was renamed or deleted. The rollup still points at the old property and returns nothing.
  • Some source cells are empty. Put a Count empty rollup next to your Sum: a result above 0 means part of your total is missing by design, because Sum skips blanks silently.
  • The source is a formula that returns text. A formula that builds a label produces a string, so numeric rollups cannot add it. Use Show original to see exactly what the rollup reads.

If the source is a formula, the fix is usually in the formula itself, and the formula reference is the fastest way to confirm what type it returns.

5. Duplicated databases and self-relations

Notion’s help center answers the duplication case directly: when you duplicate a database that has a relation, the duplicate does not appear as a relation in the original database, because Notion converts the two-way sync to a one-way sync during duplication. So if you duplicated a tracker to start a clean version, the rollups in the old database may still be reading the old table while you edit the new one. Stale or partial totals are the usual symptom.

Self-relations have a related quirk: a single-property self-relation is not fully one-way in practice. If Next and Previous have to stay separate, enable Two-way relation, name both properties, and hide the one you do not need.

6. If the value is wrong only in Zapier, Make or the API

When the number is right in Notion but blank in an integration, the app is not the problem. The API has documented limits that produce exactly this:

  • Relation values come back empty when the connection does not have access to the source database, and the same permission rule applies to complete rollup and formula results, so share every database in the chain with the connection.
  • A rollup the API cannot compute, because it depends on too many related pages or on nested formulas and rollups, is returned as an unsupported value with no partial result. Fewer related pages or flatter nesting restores it.
  • A rollup with more than 25 references is truncated in a page response, so the page property endpoint is required for the full value.
  • Rollup values cannot be updated through the API at all.

All of these behaviors are listed in the Notion API page properties reference. If you are wiring a rollup into a scheduled automation, start from the Zapier + Notion workflows so the read step matches what the API expects.

A two-minute rebuild test

Before you rebuild the real thing, reproduce the setup in two minimal databases: Customers, Items, one relation, one Number property, one rollup set to Sum. If that version calculates, copy your settings into the real database one piece at a time (relation, then source property, then calculation) and watch where the number stops matching. The check that fails is the answer.

If the whole workspace is misbehaving rather than one property, that is a different problem: see how to fix Notion sync errors. Once your database is calculating again, the Notion task system guide shows how to put those numbers to work.

FAQ

Why does my Notion rollup show nothing at all? A rollup returns no value when the row has no linked page, when the property it reads no longer exists, or when the source cells are empty. Add a second rollup with Count all: if that is empty too, the relation is empty on that row.

Why does my rollup total show 0 instead of the correct sum? The numeric calculations are documented for Number properties. If the source holds text, or a formula that returns text, there is nothing to add. Move the values into a Number property or switch to a counting calculation.

Can I type into a rollup cell or update it through the API? No. Rollups are read-only in both the app and the API. Edit the linked pages or the settings and the rollup recalculates on its own.

Why is the rollup correct in Notion but empty in Zapier or Make? The connection probably cannot see one of the databases in the chain, or the rollup is nested too deeply for the API to compute. Share the source database and simplify the nesting.

Sources

Last updated: September 18, 2026. Rollup behavior and API limits are checked against Notion’s own documentation.