Vector Database Cost Calculator (Memory Size and TCO)
Size a vector database and compare what it will cost. The calculator works out the memory your vectors need from their count and dimensions, then compares a managed-service quote with a self-hosted cluster over the period you choose. Vendor prices change often and differ by plan, so this page hardcodes none: you enter the quote and the infrastructure price you were actually given.
Vector database cost is driven mostly by memory: every vector is stored as a list of 32-bit numbers, and fast search keeps those numbers, plus an index, in RAM. This calculator turns your vector count and dimensions into a memory estimate, then compares a managed-service quote with a self-hosted cluster across the time horizon you set.
How vector database memory is estimated
The size formula follows the capacity-planning guidance published by Qdrant, an open-source vector database: memory = number of vectors × vector dimension × 4 bytes × 1.5. The extra 50% covers metadata such as indexes and point versions, and temporary segments created during optimization. Their own example, 1 million vectors of 1,024 dimensions, comes to about 5.72 GB, which is what this calculator returns for the same inputs. Change the multiplier if your engine documents a different overhead.
| Vectors | Dimensions | Raw data | RAM at 1.5× overhead |
|---|---|---|---|
| 1 million | 1,024 | 3.81 GB | 5.72 GB |
| 10 million | 1,024 | 38.15 GB | 57.22 GB |
| 50 million | 1,024 | 190.73 GB | 286.1 GB |
| 50 million | 1,024 (2 replicas) | 190.73 GB | 572.2 GB |
Vector database cost: comparing managed and self-hosted
A managed service bills by its own units (storage, reads, writes, or cluster size), so the fair way to compare is the monthly figure from the vendor's pricing calculator or sales quote for your workload. Self-hosting is priced here as RAM cost per GB per month plus the labour to run it. Worked example: 50 million vectors, 1,024 dimensions, 2 replicas need 572.2 GB of RAM. If your cloud charges $5 per GB of RAM a month and operations take $2,000 of engineer time, self-hosting costs $4,861.02 a month, or $174,996.83 over 36 months. Against a managed quote of $6,000 a month ($216,000), self-hosting is $41,003.17 cheaper. The $5, $2,000 and $6,000 in this example are illustrations, not market prices.
What the estimate leaves out
Total cost of ownership also includes generating the embeddings, storing payloads, backups, multi-region copies and data transfer. Quantization and on-disk storage can cut memory sharply at some cost in speed or recall. Query volume affects managed bills that charge per read. Add these to the monthly figures you enter if they matter for your case.
Source for the sizing formula: Qdrant documentation, Capacity Planning. Prices are your own inputs; check each vendor's current pricing page before deciding. Last updated: October 2026.