Amazon DocumentDB (with MongoDB compatibility) pricing

Pay as you go with no up-front fees. There is no minimum fee. 

On-Demand Instances let you pay by the hour with no long-term commitments or upfront fees. This frees you from the cost and complexity of planning and purchasing database capacity ahead of your needs. On-Demand pricing lets you pay as you go and is ideal for development, test and other short-lived workloads.

Pricing is per instance-hour consumed, from the time an instance is launched until it is stopped or deleted. Partial instance hours are billed in one-second increments, with a 10-minute minimum charge following a billable status change such as creating, modifying, or deleting an instance.

Instance pricing applies to both primary instances, used for read-write workloads, and Amazon DocumentDB replicas, used to scale reads and enhance failover. Amazon DocumentDB uses Multi-AZ architecture to failover to one of your replicas if an outage occurs. The cost of Multi-AZ deployments is simply the cost of the primary instance plus the cost of each Amazon DocumentDB replica. To maximize availability, we recommend placing at least one replica in a different Availability Zone from the primary instance.

Amazon DocumentDB T3 and T4g medium instances run in Unlimited mode, which means that you will be charged if your average CPU utilization over a rolling 24-hour period exceeds the baseline of the instance. CPU Credits are charged at ¥0.616 per vCPU-Hour. The CPU Credit pricing is the same for all T3 and T4g instance sizes across all regions. For more information on how unlimited burstable performance instances work and how it is priced, see Unlimited mode concepts.

Storage consumed by your Amazon DocumentDB cluster is billed per GB-month. Billable storage includes your data, indexes, and change stream data. I/Os consumed are billed per million I/O requests. Reads and writes to your storage volume count as billable I/O requests, including reads and writes from features like change streams and TTL indexes. You pay only for the storage and IOs that your Amazon DocumentDB cluster consumes, and do not need to provision these resources in advance.

Backup storage for an Amazon DocumentDB cluster is the storage associated with your automated cluster backups and any manual cluster snapshots. Increasing your backup retention period or taking manual cluster snapshots increases the backup storage consumed.

• Backup storage is allocated by region. Total backup storage space is equivalent to the sum of the storage for all backups in that region.
• Copying a snapshot to another region increases allocated backup storage in the destination region.
• There is no additional charge for backup storage of up to 100% of your total Amazon DocumentDB cluster storage for a region. There is also no additional charge for backup storage if your backup retention period is 1 day and you do not have any manual snapshots beyond the backup retention period. Backup storage beyond this amount and manual snapshots retained outside of the backup retention period, whether your cluster is active or has been deleted, are billed at storage rates in the table below.
  

The pricing below is based on data transferred “in” and “out” of Amazon DocumentDB

• Data transferred between Amazon DocumentDB and Amazon EC2 Instances in the same Availability Zone is free.
• Data transferred between Availability Zones for replication of Multi-AZ deployments is free.
• Amazon DocumentDB database instances outside VPC: For data transferred between an Amazon EC2 instance and Amazon DocumentDB database instance in different Availability Zones of the same Region, there is no Data Transfer charge for traffic in or out of the Amazon DocumentDB database instance. You are only charged for the Data Transfer in or out of the Amazon EC2 instance, and standard Amazon EC2 Regional Data Transfer charges apply.
• Amazon DocumentDB database instances inside VPC: For data transferred between an Amazon EC2 instance and Amazon DocumentDB database instance in different Availability Zones of the same Region, Amazon EC2 Regional Data Transfer charges apply on both sides of transfer.