Storage Capacity Planner

Planning storage for retention and growth

Storage planning starts with how much data arrives each day and how long you must keep it. Multiply daily ingest by retention days to estimate the baseline dataset size. Replication multiplies that requirement to protect against failures, while compression reduces it based on how effectively your data can be compressed. The result is the usable storage you need to meet retention and resiliency targets.

Real storage systems require overhead for filesystems, metadata, snapshots, and operational buffers. Overhead varies by platform and workload, so this calculator lets you set a percentage that reflects your environment. Growth is applied on top of the overhead using a compounded monthly rate. This models the reality that data volume tends to increase month after month, not just in a single step.

The output distinguishes between usable storage (what your workload consumes after replication and compression) and raw storage (what you must purchase and provision). Use the raw figure to size arrays, racks, and budgets, and use the usable figure to communicate requirements to application owners. All calculations are performed in your browser for privacy and speed, making it easy to test multiple growth scenarios before you commit.

Compression ratios can vary widely by data type. Text logs, JSON, and columnar data often compress well, while images, video, and encrypted data compress poorly. If you are unsure, test real samples or use a conservative ratio like 1.2 to avoid underestimating capacity. Replication factors depend on your availability model; a 2x factor may be sufficient for many systems, while 3x is common in distributed storage for higher fault tolerance.

Consider how retention policies apply across tiers. Some organizations keep hot data on faster storage and move older data to cheaper tiers. If you plan to tier data, run separate calculations for each tier rather than combining everything into a single number. This estimator gives a strong baseline, but storage architecture, backup strategy, and compliance requirements all influence the final sizing decision.

Formula

Base usable (GB): dailyGB × retentionDays × replication ÷ compression

Usable (TB): baseGB ÷ 1024

Raw (TB): baseGB × (1 + overhead/100) × (1 + growth/100)^months ÷ 1024

Example calculation

If you ingest 500 GB per day, retain for 30 days, replicate 2x, and compress by 1.5x, base usable storage is 500 × 30 × 2 ÷ 1.5 = 20,000 GB or about 19.53 TB.

With 20 percent overhead and 5 percent monthly growth over 12 months, raw storage becomes 20,000 × 1.2 × 1.05^12 ≈ 32,300 GB or roughly 31.5 TB.

FAQs

What is the base storage calculation?

Base storage equals daily ingest multiplied by retention and replication, divided by compression.

What does overhead include?

Overhead represents filesystem reserves, snapshots, metadata, and operational buffers.

How is growth applied?

Growth is compounded monthly across the planning horizon.

Can I enter data in TB?

Yes. Use the unit selector next to the daily ingest field.

Is this private?

Yes. All calculations run locally.

How it works

This tool converts ingest and retention into base storage, then layers on overhead and growth to estimate raw capacity.

Disclaimer

Storage estimates are simplified and should be validated against your platform's sizing guidelines.