# AWS RDS pricing explained: instances, storage, Multi-AZ and real Postgres bills

> How Amazon RDS for PostgreSQL bills instances, gp3 storage, Multi-AZ, backups, CPU credits, Extended Support and transfer, with three worked monthly bills.

- **Published:** 2026-10-27
- **Author:** Abhishek Jaiswal
- **Section:** Compare (https://ownkube.io/compare)
- **Tags:** aws, rds, aws-rds-pricing, postgres, managed-postgres, cloud-cost
- **Canonical URL:** https://ownkube.io/compare/aws-rds-pricing-explained
- **Cover:** https://ownkube.io/blog/aws-rds-pricing-explained.png

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Amazon RDS bills a database on several meters at once: an hourly rate for the instance class, storage per GB-month, backup storage past a free allowance, data transfer out, and a few lines that only some databases hit (CPU credits on burstable instances, Extended Support on old Postgres versions, a public IPv4 address).

Multi-AZ doubles the instance and storage lines. The smallest RDS for PostgreSQL instance, `db.t4g.micro`, is $0.016 an hour in US East (N. Virginia), about $11.68 a month before storage.

This post walks through each line for RDS for PostgreSQL, from AWS's published On-Demand prices for US East (N. Virginia) as of 2026-10-27, and works three monthly bills.

**TL;DR**

- Instances bill by the hour. `db.t4g.micro` (2 vCPU, 1 GiB) is about $11.68 a month, `db.t4g.medium` (2 vCPU, 4 GiB) about $47.45 and `db.m7g.large` (2 vCPU, 8 GiB) about $122.64.
- Multi-AZ adds a standby in a second Availability Zone and doubles the instance and storage price.
- gp3 storage is $0.115 per GB-month, or $0.23 with Multi-AZ. Backup storage up to the size of your databases is free, then $0.095 per GB-month.
- Burstable `t4g` instances bill $0.075 per vCPU-hour for CPU above their baseline, and versions past standard support bill Extended Support from $0.100 per vCPU-hour.
- A small production Postgres with a standby and 50 GB lands around $106 a month on RDS.

## How does RDS pricing work?

| Line | How it bills | US East (N. Virginia) rate |
|---|---|---|
| Instance | Per hour, by instance class and deployment | from $0.016 an hour |
| Storage (gp3) | Per GB-month provisioned | $0.115 Single-AZ, $0.23 Multi-AZ |
| Backup storage | Per GB-month past the free allowance | $0.095 |
| CPU credits | Per vCPU-hour above baseline, `t4g` and `t3` only | $0.075 |
| Extended Support | Per vCPU-hour, Postgres versions past standard support | from $0.100 |
| Data transfer out | Per GB to the internet | first 100 GB a month free across AWS, then from $0.09 |
| Public IPv4 | Per hour, if the database is publicly accessible | $0.005 an hour |

You pick an instance class and a storage size up front, and RDS bills them for every hour the database exists, busy or idle. A stopped RDS instance stops the instance meter but keeps billing storage, and AWS starts it again after seven days.

## What do RDS for PostgreSQL instances cost?

On-Demand prices for PostgreSQL in US East (N. Virginia):

| Instance | vCPU | Memory | Single-AZ hourly | Single-AZ a month | Multi-AZ a month |
|---|---|---|---|---|---|
| db.t4g.micro | 2 | 1 GiB | $0.016 | $11.68 | $23.36 |
| db.t4g.small | 2 | 2 GiB | $0.032 | $23.36 | $47.45 |
| db.t4g.medium | 2 | 4 GiB | $0.065 | $47.45 | $94.17 |
| db.t4g.large | 2 | 8 GiB | $0.129 | $94.17 | $188.34 |
| db.m7g.large | 2 | 8 GiB | $0.168 | $122.64 | $246.01 |
| db.r7g.large | 2 | 16 GiB | $0.239 | $174.47 | $348.94 |

Monthly figures use 730 hours. Prices vary by region. In EU (Frankfurt), `db.t4g.micro` is $0.019 an hour and `db.m7g.large` $0.200.

The `t4g` classes are burstable. Each one earns CPU credits at a baseline rate and spends them when busy. RDS runs them in Unlimited mode, so a database that stays above baseline for a rolling 24 hours bills $0.075 per vCPU-hour for the extra. A busy database on a small `t4g` can cost more than the next class up. The `m7g` (general purpose) and `r7g` (memory optimized) classes have no credit system.

Reserved Instances with a one-year or three-year commitment lower the hourly rate. They suit a database whose size you are sure of for that long.

## What does Multi-AZ cost?

Multi-AZ runs a synchronous standby in a second Availability Zone. If the primary fails, RDS fails over to the standby, usually within a minute or two. You pay for the standby as a full instance, and storage bills at the Multi-AZ rate ($0.23 instead of $0.115 per GB on gp3). In practice, Multi-AZ doubles the database bill.

The standby in a classic Multi-AZ instance serves no reads. Read traffic needs a read replica, which bills as another instance plus its own storage. RDS also offers Multi-AZ DB clusters, with two readable standbys, at a different price per instance.

## How much is RDS storage and backup?

gp3 is the default General Purpose SSD:

| Item | Single-AZ | Multi-AZ |
|---|---|---|
| Storage | $0.115 per GB-month | $0.23 per GB-month |
| Provisioned IOPS above baseline | $0.02 per IOPS-month | $0.04 per IOPS-month |

Volumes under 400 GB get a baseline of 3,000 IOPS and 125 MiB/s, which covers most small databases. Storage bills on the size you provision, however much of it you use, and RDS storage can grow but never shrink. A volume you sized for a one-off import keeps billing at that size.

Automated backups are free up to 100% of the total provisioned storage of your databases in the region. Past that, and for manual snapshots you keep, backup storage is $0.095 per GB-month. A 7-day retention window on a database with a high write rate can pass the free amount, because each day's changes are kept.

Point-in-time restore is part of automated backups. You can restore to any second within the retention window, from 1 to 35 days, at no charge beyond the backup storage.

## What are the RDS charges people miss?

### Extended Support

When a Postgres major version reaches the end of RDS standard support, RDS keeps running it under Extended Support and adds a charge per vCPU-hour: from $0.100 in the first two years and $0.200 in the third. A `db.t4g.medium` has 2 vCPUs, so Extended Support adds about $146 a month to a $47 instance. Upgrading the major version stops the charge.

### Public IPv4

AWS bills every public IPv4 address at $0.005 an hour, about $3.65 a month. A publicly accessible RDS instance has one. A database reached only from inside the VPC does not.

### Data transfer

Data out to the internet is free for the first 100 GB a month across your AWS account, then starts at $0.09 per GB. Traffic between Availability Zones bills too, so an app in one zone reading from a database in another pays for both directions.

## What do real RDS bills look like?

All three are On-Demand in US East (N. Virginia) and assume the database runs all month.

### A side project

`db.t4g.micro`, Single-AZ, 20 GB of gp3, private to the VPC.

| Line | Monthly |
|---|---|
| Instance | $11.68 |
| Storage (20 GB at $0.115) | $2.30 |
| Backups (inside the free allowance) | $0 |
| **Total** | **$13.98** |

Make it publicly accessible and add $3.65 for the IPv4 address.

### A small production database

`db.t4g.medium`, Multi-AZ, 50 GB of gp3.

| Line | Monthly |
|---|---|
| Instance (Multi-AZ) | $94.17 |
| Storage (50 GB at $0.23) | $11.50 |
| Backups (inside the free allowance) | $0 |
| **Total** | **$105.67** |

### A busier app

`db.m7g.large`, Multi-AZ, 200 GB of gp3, plus one read replica on the same class.

| Line | Monthly |
|---|---|
| Instance (Multi-AZ) | $246.01 |
| Storage (200 GB at $0.23) | $46.00 |
| Read replica instance | $122.64 |
| Read replica storage (200 GB at $0.115) | $23.00 |
| **Total** | **$437.65** |

None of the three includes the work around RDS: the VPC, subnet groups, security groups, parameter groups, IAM and monitoring that someone sets up and keeps up to date.

## What does the same Postgres cost on a flat box?

Ownkube runs managed PostgreSQL 17 and 18 on flat database boxes, with storage at $0.25 per GB a month that includes 7-day backups with point-in-time restore on Personal and Team.

| Setup | RDS (US East) | Ownkube |
|---|---|---|
| 1 GiB, 20 GB, single instance | $13.98 (`db.t4g.micro`) | $13 (DB 1 at $8, plus 20 GB) |
| 4 GiB, 50 GB, with a standby | $105.67 (`db.t4g.medium` Multi-AZ) | $81 (DB 4 at $28 twice, plus 50 GB on each) |
| 8 GiB, 200 GB, with a standby | $292.01 (`db.m7g.large` Multi-AZ) | $208 (DB 8 at $54 twice, plus 200 GB on each) |

At the smallest size, RDS and Ownkube cost about the same, and `db.t4g.micro` has more vCPUs on paper. The gap opens with a standby and more data, because Ownkube's standby bills as one more flat box and its storage price already covers backups. Standbys with automatic failover are on the Team plan.

The other difference is setup. On Ownkube there is no AWS account, VPC or security group to configure. The database is private by default, and linking it to an app sets the connection string as an environment variable.

AWS also sells fixed-price databases outside RDS. Lightsail managed databases start at $15 a month for 1 GB of memory and 40 GB of storage, and [AWS Lightsail pricing explained](/compare/aws-lightsail-pricing-explained) covers its plans.

## When to stay on RDS

Stay on RDS if:

- The rest of your stack runs in AWS and the database needs to sit in the same VPC.
- You need a region Ownkube does not run in. Ownkube Compute runs in Germany and Mumbai.
- You want Reserved Instance pricing on a database you are sure of for three years.
- You need more than two standbys, or compliance programs tied to your AWS account.

If you have the AWS skills on hand, RDS is a mature, well-documented service.

## FAQ

### How much does AWS RDS cost a month?

The smallest RDS for PostgreSQL instance, `db.t4g.micro`, is about $11.68 a month in US East (N. Virginia), plus $0.115 per GB of gp3 storage. A small production database with Multi-AZ and 50 GB is about $106 a month.

### Is RDS free?

New AWS accounts get free-tier usage that covers a Single-AZ micro instance for 750 hours a month, 20 GB of General Purpose storage and 20 GB of backup storage, for 12 months. After that, On-Demand prices apply.

### Does Multi-AZ double the RDS price?

Close to it. You pay for the standby instance at the same hourly rate as the primary, and gp3 storage bills at $0.23 per GB-month instead of $0.115.

### Why is my RDS bill higher than the instance price?

The usual causes are CPU credits on a busy `t4g` instance, Extended Support on an old Postgres version, backup storage past the free allowance, storage provisioned larger than you use, and data transfer between Availability Zones.

### What is the cheapest RDS for PostgreSQL instance?

`db.t4g.micro` with 2 burstable vCPUs and 1 GiB of memory, at $0.016 an hour in US East (N. Virginia).

## Where Ownkube fits

If you want managed Postgres without an AWS account to run, Ownkube gives you PostgreSQL 17 or 18 on a flat box from $4 a month, backups in the storage price on Personal and Team, and a standby with automatic failover on Team, next to the app that uses it. Compare more providers in [managed Postgres pricing compared](/compare/managed-postgres-pricing), or price your own setup with the [managed Postgres cost calculator](/tools/managed-postgres-cost-calculator). [Deploy my first app](https://app.ownkube.io/login).

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