Backup files of an instance occupy the backup space. Each RDS instance provides the backup space with a certain free quota. Additional charges can be incurred for the backup space exceeding the free quota. For information about billing standards for backup space usage, see RDS pricing. Different types of instances have different free backup space quotas. This document describes how to view and calculate the free quota of the instance backup space.

Formula for calculating the free quota of the backup space

If the total volume of your backup data (OSS and Archive Storage) and backup log (OSS) is less than or equal to 50% of the storage space bought for the instance, the space is within the free quota.

The excess backup space beyond the free quota is billed by hour. (Unit: GB, rounded up only)
Costs per hour = data backup volume + Log backup volume - Instance storage space x 50% 

View the free quota of the backup space on the RDS console

  1. Log on to the RDS console.
  2. Select the region where the target instance is located.
  3. Click the ID of the target instance to go to the Basic Information page.
  4. In the Resource Information area at the bottom of the page, check the remarks next to Backup Size, which shows the free quota, as in the following figure.
    Instances of different types support different free quotas. The following figure is only an example.