OpenSearch Vector Cost Calculator
Estimate OpenSearch Serverless compute and storage cost.
With the default inputs, $693.60/month — 4 OCUs + 100 GB. Enter your own numbers below to recompute instantly; the full step-by-step math is shown under the worked example.
Results update automatically as you type.
- • OpenSearch Serverless approximation; minimum OCUs may apply.
- Compute (OCU)
- $691.20
- Storage
- $2.40
- Total / month
- $693.60
Estimate the monthly cost of Amazon OpenSearch Serverless for vector search from OCU compute units and stored data.
How this is calculated
Monthly cost = OCUs × $/OCU-hour × 730 hours + storage (GB) × $/GB-month. OpenSearch Serverless prices compute in OpenSearch Compute Units (OCUs) plus stored data, and enforces a minimum number of OCUs — so small stores still pay baseline compute.
Is this a good result? What to do next
OpenSearch is pricey for small vector workloads because of the OCU minimum — below that threshold a managed vector DB is often cheaper. It becomes competitive at larger scale where you're actually using the compute you pay for.
Typical planning ranges
- Priced on
- OCU-hours + storage
- OCU minimum
- baseline cost even when idle
- Small stores
- a managed vector DB may be cheaper
Ranges are typical planning figures to sanity-check your result, not authoritative benchmarks. Your numbers will vary with use case, volume, and vendor.
How to improve this number
- Consolidate indexes to use fewer OCUs.
- Right-size OCUs to real query load.
- Compare against a dedicated managed vector DB below the OCU floor.
Common mistakes
- Running OpenSearch Serverless for a tiny vector set.
- Ignoring the OCU minimum in the estimate.
When to use a different approach
For raw vector storage sizing, use the vector database storage calculator. For the full RAG pipeline, use the RAG cost calculator.
Worked example (defaults)
With the default inputs above, here is the result:
- • OpenSearch Serverless approximation; minimum OCUs may apply.
- Compute (OCU)
- $691.20
- Storage
- $2.40
- Total / month
- $693.60
Sources & references
Frequently asked questions
Why is OpenSearch pricey for small workloads?+
Serverless enforces a minimum number of OCUs, so small vector stores still pay for baseline compute. A managed vector DB may be cheaper below that threshold.