Azure Cosmos DB is a globally distributed, multi-model database service that enables you to harness the benefits of global distribution, elastic scalability, and low latency. Pricing for Azure Cosmos DB is based on the capacity consumed and the services used.
The cost of reading and writing data is measured in Request Units (RUs). A RU is a normalized measure of CPU, memory, and IOPS required to perform a database operation. The number of RUs consumed by an operation depends on the operation type, the item size, and the number of partitions accessed.
Azure Cosmos DB offers several throughput provisioning models and API options, each with slightly different pricing characteristics:
Below is a simplified representation. For exact and up-to-date pricing, please refer to the official Azure Cosmos DB pricing page.
| Service / Unit | Region | Price (USD) |
|---|---|---|
| Autoscale Throughput (1000 RUs/sec) | East US | $0.030 per hour |
| Manual Throughput (1000 RUs/sec) | East US | $0.023 per hour |
| Serverless (1000 RUs) | East US | $0.00000035 per RU |
| Storage (GB/month) | East US | $0.088 per GB |
| Backup Storage (GB/month) | East US | $0.044 per GB |
A simple GET operation for an item might cost 1 RU. A more complex query involving multiple partitions could cost significantly more. The Azure portal and SDKs provide tools to monitor RU consumption.
For example, reading a 1KB item with consistent properties costs 1 RU.
1 KB read = 1 RU
Writing a 1KB item with consistent properties costs 2 RUs (typically read operations cost less than write operations).
1 KB write = 2 RU
Azure Cosmos DB offers a free tier that provides a limited amount of RUs and storage for development and testing purposes. This is a great way to get started without upfront costs.
Azure provides various tools to help you manage and optimize your Cosmos DB costs, including: