What are Azure SQL Database service tiers?

Azure SQL Database offers Basic, Standard, and Premium service tiers for both single databases and elastic pools. Service tiers are primarily differentiated by a range of performance level and storage size choices, and price. All service tiers provide flexibility in changing performance level and storage size. Single databases and elastic pools are billed hourly based on service tier, performance level, and storage size.

Choosing a service tier

Choosing a service tier depends primarily on business continuity, storage, and performance requirements.

Basic Standard Premium
Target workload Development and production Development and production Development and production
Uptime SLA 99.99% 99.99% 99.99%
Backup retention 7 days 35 days 35 days
CPU Low Low, Medium, High Medium, High
IO throughput Low Medium Order of magnitude higher than Standard
IO latency Higher than Premium Higher than Premium Lower than Basic and Standard
Columnstore indexing and in-memory OLTP N/A N/A Supported

Performance level and storage size limits

Performance levels are expressed in terms of Database Transaction Units (DTUs) for single databases and elastic Database Transaction Units (eDTUs) for elastic pools. For more on DTUs and eDTUs, see What are DTUs and eDTUs?

Single databases

Basic Standard Premium
Maximum storage size* 2 GB 1 TB 4 TB
Maximum DTUs 5 3000 4000

Elastic pools

Basic Standard Premium
Maximum storage size per database* 2 GB 1 TB 1 TB
Maximum storage size per pool* 156 GB 4 TB 4 TB
Maximum eDTUs per database 5 3000 4000
Maximum eDTUs per pool 1600 3000 4000
Maximum number of databases per pool 500 500 100


* Storage sizes greater than the amount of included storage are in preview and extra costs apply. For details, see SQL Database pricing.

* In the Premium tier, more than 1 TB of storage is currently available in the following regions: Australia East, Australia Southeast, Brazil South, Canada Central, Canada East, Central US, France Central, Germany Central, Japan East, Japan West, Korea Central, North Central US, North Europe, South Central US, South East Asia, UK South, UK West, US East2, West US, US Gov Virginia, and West Europe. See P11-P15 Current Limitations.

For details on specific performance levels and storage size choices available, see SQL Database resource limits.

Next steps