Observability capacity planning

Tools for people
who run systems.

Estimate telemetry capacity, compare architectures and plan with confidence.

Start planningExplore tools

Free · No signup · Calculated in your browser

Where do I start?

Start with what you know

Pick the number you already have. You can change course at any step.

I know my EPSEvents/sec + average event sizeGet your daily ingest in GB/day. I know my daily ingestGB/day or TB/dayAdd retention and growth, then continue to a platform.
I already know my platformOpen its calculator directly
SplunkElasticsearchGrafana LokiOpenSearch
Capacity Planning

Platform capacity calculators

Reference scenario Each figure is that tool's own default model for the same input: different quantities, not rankings.

Splunk

Classic + SmartStore

Inputs GB/day · retention · RF/SF

Local storage on indexers (classic, RF2/SF2)28.1 TBReference: 250 GB/day · 90 days · 25% growth
Open calculator

Elasticsearch

Hot · Warm · Cold · Frozen

Inputs GB/day · tier days · replicas

Provisioned local disk, 1 replica66.2 TBReference: 250 GB/day · 90 days · 25% growth
Open calculator

Grafana Loki

Object storage · WAL

Inputs GB/day · retention · replication

Object storage dataset, one copy (not node disk)28.1 TBReference: 250 GB/day · 90 days · 25% growth
Open calculator

OpenSearch

Amazon · Self-managed

Inputs GB/day · retention · replicas

Hot storage to provision (Amazon OpenSearch Service)81.4 TBReference: 250 GB/day · 90 days · 25% growth
Open calculator

Compare all four with your numbers →Looking for cron, YAML or timestamps? See all tools →

Why ObservKit

Numbers you can check

Read the methodology →

  • Transparent formulas

    Every result shows its math.

  • Adjustable assumptions

    Expert mode exposes ratios, caches and shard settings.

  • Sources and limitations

    Assumptions link to vendor documentation and state their limits.

  • No signup required

    Open a calculator and get a result.

  • Compare architectures

    Put two scenarios side by side, or continue the same input in another platform.

  • Privacy first

    Calculations run in your browser; your inputs are not uploaded.

Workflow

From a number to a plan

See the full workflow →

  1. 1

    Enter data

    EPS or GB/day, plus retention.

  2. 2

    Size

    Pick a platform and read its capacity.

  3. 3

    Compare

    Two scenarios, or another platform.

  4. 4

    Plan

    Save, share or print a report.

Guides

Choose the inputs, not just the formula

View all guides →

Grafana Loki sizingObject storage, WAL, replication and what the published compute profiles do not tell you.OpenSearch sizingShards, replicas, storage tiers, and Amazon OpenSearch Service versus self-managed.Elasticsearch data tiersDays per tier, local disk versus snapshot repository and the utilization target.Splunk SmartStoreCache versus retention, hot-bucket replicas and when SmartStore pays off.