per vCPU-Hour of T3 CPU Credits


Why am I getting billed for that ? i am using RDS db.t3.micro and shoud included on free tier

asked 17 days ago332 views
2 Answers


If you look at the shared bill image, you will see that you are being charged for burst credits.
T3-based instance types can burst beyond their performance when loaded.
Bursting will incur additional charges as described in the documentation below.

While Amazon RDS T2 instances are restricted to baseline performance once the CPU Credit balance is drawn down to zero, Amazon RDS T3 instances can burst above the baseline even when its CPU Credit balance is zero. For a vast majority of database workloads where the average CPU utilization is at or below the baseline performance, the basic hourly price for t3.small covers all CPU bursts. If the instance happens to run at an average 25% CPU utilization (5% above baseline) over a period of 24 hours after its CPU Credit balance is drawn to zero, it will be charged an additional 9 cents (7.5 cents/vCPU-hour x 1 vCPU x 5% x 24 hours). See Amazon RDS Pricing for pricing details.

profile picture
answered 17 days ago
profile pictureAWS
reviewed 17 days ago

Enter image description here

answered 17 days ago
  • From the screenshot you provided, you are paying 25.035 vCPU-Hours as you have exceeded the average CPU utilization. $0.144 is the rate for CPU Credits.

    T3 CPU Credits Amazon RDS for SQL Serever T3 DB 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 $0.144 per vCPU-Hour. The CPU Credit pricing is the same for all T3 instance sizes across all Regions and is not covered by Reserved Instances.

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions