> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt

# db.collection.estimatedDocumentCount() (mongosh method)

## Definition

Returns the count of all documents in a collection or view.

```javascript
db.collection.estimatedDocumentCount( <options> )
```

### Parameters

| Parameter | Type | Description |
| --- | --- | --- |
| options | document | Optional. Extra options that affect the count behavior. |

## Fields

The `options` document can contain the following:

| Field | Type | Description |
| --- | --- | --- |
| `maxTimeMS` | integer | Optional. The maximum amount of time to allow the count to run. |

## Compatibility

This method is available in deployments hosted in the following environments:

- [MongoDB Atlas](https://www.mongodb.com/docs/atlas): The fully managed service for MongoDB deployments in the cloud

**Note:**

This command is supported in all MongoDB Atlas clusters. For information on Atlas support for all commands, see [Unsupported Commands.](https://www.mongodb.com/docs/atlas/unsupported-commands/)

- [MongoDB Enterprise](https://www.mongodb.com/docs/manual/administration/install-enterprise.md#std-label-install-mdb-enterprise): The subscription-based, self-managed version of MongoDB

- [MongoDB Community](https://www.mongodb.com/docs/manual/administration/install-community.md#std-label-install-mdb-community-edition): The source-available, free-to-use, and self-managed version of MongoDB

## Behavior

### Mechanics

[`db.collection.estimatedDocumentCount()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.estimateddocumentcount.md#mongodb-method-db.collection.estimatedDocumentCount) does not take a query filter and instead uses metadata to return the count for a collection.

For a [view:](https://www.mongodb.com/docs/manual/core/views.md#std-label-views-landing-page)

- There is no metadata.

- The document count is calculated by executing the [aggregation pipeline](https://www.mongodb.com/docs/manual/core/aggregation-pipeline.md#std-label-aggregation-pipeline) in the view definition.

- There is no fast estimated document count.

### Sharded Clusters

On a sharded cluster, the resulting count will not correctly filter out [orphaned documents.](https://www.mongodb.com/docs/manual/reference/glossary.md#std-term-orphaned-document)

### Unclean Shutdown

This section only applies to collections.

After an unclean shutdown, the count may be incorrect.

After an unclean shutdown of a [`mongod`](https://www.mongodb.com/docs/manual/reference/program/mongod.md#mongodb-binary-bin.mongod) using the [Wired Tiger](https://www.mongodb.com/docs/manual/core/wiredtiger.md) storage engine, count statistics reported by [`db.collection.estimatedDocumentCount()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.estimateddocumentcount.md#mongodb-method-db.collection.estimatedDocumentCount) may be inaccurate.

The amount of drift depends on the number of insert, update, or delete operations performed between the last [checkpoint](https://www.mongodb.com/docs/manual/core/wiredtiger.md#std-label-storage-wiredtiger-checkpoints) and the unclean shutdown. Checkpoints usually occur every 60 seconds. However, [`mongod`](https://www.mongodb.com/docs/manual/reference/program/mongod.md#mongodb-binary-bin.mongod) instances running with non-default [`--syncdelay`](https://www.mongodb.com/docs/manual/reference/program/mongod.md#std-option-mongod.--syncdelay) settings may have more or less frequent checkpoints.

Run [`validate`](https://www.mongodb.com/docs/manual/reference/command/validate.md#mongodb-dbcommand-dbcmd.validate) on each collection on the [`mongod`](https://www.mongodb.com/docs/manual/reference/program/mongod.md#mongodb-binary-bin.mongod) to restore statistics after an unclean shutdown.

After an unclean shutdown:

- [`validate`](https://www.mongodb.com/docs/manual/reference/command/validate.md#mongodb-dbcommand-dbcmd.validate) updates the [count statistic](https://www.mongodb.com/docs/manual/reference/operator/aggregation/collstats.md#std-label-collstat-count) in the [`collStats`](https://www.mongodb.com/docs/manual/reference/command/collstats.md#mongodb-dbcommand-dbcmd.collStats) [output](https://www.mongodb.com/docs/manual/reference/command/collstats.md#std-label-collStats-output) with the latest value.

- Other statistics like the number of documents inserted or removed in the [`collStats`](https://www.mongodb.com/docs/manual/reference/command/collstats.md#mongodb-dbcommand-dbcmd.collStats) [output](https://www.mongodb.com/docs/manual/reference/command/collstats.md#std-label-collStats-output) are estimates.

### Client Disconnection

If the client that issued [`db.collection.estimatedDocumentCount()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.estimateddocumentcount.md#mongodb-method-db.collection.estimatedDocumentCount) disconnects before the operation completes, MongoDB marks [`db.collection.estimatedDocumentCount()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.estimateddocumentcount.md#mongodb-method-db.collection.estimatedDocumentCount) for termination using [`killOp`.](https://www.mongodb.com/docs/manual/reference/command/killop.md#mongodb-dbcommand-dbcmd.killOp)

### Count and Transactions

When you use [`db.collection.estimatedDocumentCount()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.estimateddocumentcount.md#mongodb-method-db.collection.estimatedDocumentCount) in a transaction, the resulting count will not filter out any uncommitted [multi-document transactions.](https://www.mongodb.com/docs/manual/core/transactions.md#std-label-transactions)

## Example

The examples on this page use data from the [sample\_mflix dataset](https://www.mongodb.com/docs/manual/sample-data/sample-mflix.md#std-label-sample-mflix). For details on how to load this dataset into your self-managed MongoDB deployment, see [Load the Sample Dataset](https://www.mongodb.com/docs/manual/sample-data/load-sample-data-local.md#std-label-sample-dataset-local). If you made any modifications to the sample databases, you may need to drop and recreate the databases to run the examples on this page.

The following example uses [`db.collection.estimatedDocumentCount()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.estimateddocumentcount.md#mongodb-method-db.collection.estimatedDocumentCount) to retrieve the count of all documents in the `movies` collection:

```javascript
db.movies.estimatedDocumentCount({})

```

**Output:**

```javascript
21349

```

**See also:**

- [`db.collection.countDocuments()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.countdocuments.md#mongodb-method-db.collection.countDocuments)

- [`count`](https://www.mongodb.com/docs/manual/reference/command/count.md#mongodb-dbcommand-dbcmd.count)

- [collStats pipeline stage with the count](https://www.mongodb.com/docs/manual/reference/operator/aggregation/collstats.md#std-label-collstat-count) option