Neptune Cluster Calculator
Size an Amazon Neptune cluster from graph size and query rate, then price instances, cluster storage and graph I/O.
About Neptune Cluster Calculator
Neptune storage is estimated from element counts because a graph's footprint is dominated by adjacency lists and property values rather than by rows, and it is billed in the same shared-volume model as Aurora with a 10 GB minimum. Reads scale out across up to 15 replicas, but a graph traversal touches many pages per query, so the per-million I/O charge often outgrows instance-hours on deep multi-hop workloads. Every rate here is an editable input with a realistic us-east-1 default, so confirm current Neptune prices with AWS for your region. Traversal depth, not data volume, is what makes a graph workload expensive — modelling I/O per query is how you discover that a three-hop query pattern costs more in I/O than the whole reader fleet costs in compute.
Formula
Neptune Cluster
graph bytes = vertices × bytes per vertex + edges × bytes per edge; instances = 1 writer + ceil(QPS ÷ per-instance QPS), capped at 16; I/O millions = QPS × I/O per query × 2,628,000 ÷ 1,000,000.
- 16
- One writer plus the 15-replica maximum for a Neptune cluster
- graph bytes
- Adjacency and property storage estimated from element counts
- writer
- Single primary instance — Neptune accepts writes on one node only
- I/O per query
- Pages the storage layer touches for one traversal
Worked example
With the default values below, Neptune Cluster Calculator returns Estimated Monthly Cost of $2,911.92. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Vertices in the graphaccepts 0–100,000,000,000 vertices
- 50,000,000 vertices
- Edges in the graphaccepts 0–100,000,000,000 edges
- 200,000,000 edges
- Average bytes per vertexaccepts 16–8,192 bytes
- 256 bytes
- Average bytes per edgeaccepts 16–8,192 bytes
- 128 bytes
- Peak query rateaccepts 0–1,000,000 queries/s
- 1,200 queries/s
- Query capacity of one instanceaccepts 1–100,000 queries/s
- 400 queries/s
- Storage I/O per queryaccepts 0–1,000 requests
- 3 requests
- Instance priceminimum 0 $/hour
- 0.348 $/hour
- Billed hours per monthaccepts 0–744 hours
- 730 hours
- Storage priceminimum 0 $/GB-month
- 0.1 $/GB-month
- I/O priceminimum 0 $/million
- 0.2 $/million
Results
- Estimated Monthly Cost
- $2,911.92
- Instances in the Cluster
- 4 instances
- Graph Storage
- 35.8 GB
- Graph Storage
- 36 GiB
- Cluster Storage
- $3.60
- Graph I/O
- $1,892.16
Step by step
- 1Values used
- 2Neptune Cluster
- 3Estimated Monthly Cost= 2,911.92
- 4Instances in the Cluster= 4 instances
- 5Graph Storage= 35.8 GB
- 6Graph Storage= 38,400,000,000
- 7Cluster Storage= 3.60
- 8Graph I/O= 1,892.16
Assumptions and limits
- The result is derived only from the 11 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Neptune Cluster calculated?
graph bytes = vertices × bytes per vertex + edges × bytes per edge; instances = 1 writer + ceil(QPS ÷ per-instance QPS), capped at 16; I/O millions = QPS × I/O per query × 2,628,000 ÷ 1,000,000. Neptune storage is estimated from element counts because a graph's footprint is dominated by adjacency lists and property values rather than by rows, and it is billed in the same shared-volume model as Aurora with a 10 GB minimum. Reads scale out across up to 15 replicas, but a graph traversal touches many pages per query, so the per-million I/O charge often outgrows instance-hours on deep multi-hop workloads. Every rate here is an editable input with a realistic us-east-1 default, so confirm current Neptune prices with AWS for your region.
Why does Neptune Cluster matter?
Traversal depth, not data volume, is what makes a graph workload expensive — modelling I/O per query is how you discover that a three-hop query pattern costs more in I/O than the whole reader fleet costs in compute.
What values do I need to enter?
This calculator takes 11 inputs: Vertices in the graph, Edges in the graph, Average bytes per vertex, Average bytes per edge, Peak query rate, Query capacity of one instance, Storage I/O per query, Instance price, Billed hours per month, Storage price, I/O price. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Why cap instances at 16?
A Neptune cluster supports one writer and up to 15 read replicas. Beyond that you need to partition the graph across clusters or move to a Neptune Analytics graph for heavy analytical traversals.