Amazon RDS is billed based on the following components:

• DB instance hours (per hour) – Billed by the hour based on instance class.
• Billed to the second with a 10-minute minimum.
• Storage (per GiB per month) – Based on your provisioned storage capacity. It is prorated if capacity changes.
• I/O requests (per 1 million requests) – Billed for Amazon RDS magnetic storage only.
• Provisioned IOPS (per IOPS per month) – Billed for Amazon RDS Provisioned IOPS and General Purpose (SSD) gp3 storage.
• Backup storage (per GiB per month) – Billed for automated database backups and snapshots. Increased retention or snapshots increase storage.
• Data transfer (per GB) – Billed for data transfer to and from your DB instance to the internet and other AWS regions.

Amazon RDS offers several purchasing options to help optimize costs based on your needs.

• On-demand instances – Billed only for instance hours used, down to the second, with a 10-minute minimum
• Reserved instances – Significant discount compared to on-demand pricing