Block Storage Cost Calculator

About the Block Storage Cost Calculator

Cloud block storage (AWS EBS, Azure Managed Disks, Google Persistent Disks) bills on three dimensions: volume size in GB, provisioned IOPS, and provisioned throughput. A simple gp3 volume with 100 GB at baseline IOPS costs about $8/month, but an io2 volume with 100 GB and 10,000 provisioned IOPS costs over $660/month. Understanding these cost levers is essential for controlling cloud compute spending.

This calculator models all three cost components for cloud block storage. Enter the volume size, IOPS requirements, and throughput needs along with the per-unit rates, and get a clear monthly cost estimate. It's perfect for right-sizing volumes, comparing storage tiers, and building accurate cloud budgets.

When This Page Helps

Block storage costs can vary 100× depending on performance tier and provisioned IOPS. This calculator helps you right-size volumes and avoid over-provisioning. Compare GP, IO-optimized, and throughput-optimized tiers to find the cheapest option for your workload.

How to Use the Inputs

1. Enter the volume size in GB.
2. Enter the per-GB monthly storage rate.
3. Enter the provisioned IOPS (above free baseline).
4. Enter the IOPS rate per provisioned IOP.
5. Enter the provisioned throughput in MB/s (above free baseline).
6. Enter the throughput rate per MB/s.
7. Review the total monthly and annual cost.

Example Calculation

Tips & Best Practices

• AWS gp3 includes 3,000 IOPS and 125 MB/s free—only pay for additional performance.
• Use CloudWatch/Azure Monitor to check actual IOPS usage before sizing; most volumes are over-provisioned.
• Snapshot your volumes before resizing—volume type changes are supported but risky without backup.
• io2 and ultra disks are for databases needing deterministic latency—use gp3 for everything else.
• Throughput costs are low—adding throughput is usually the cheapest performance boost.
• Review and right-size monthly; workloads change and over-provisioned IOPS waste money.

Right-Sizing Block Storage

The most common block storage waste is over-provisioned IOPS. A gp3 volume at $0.08/GB costs $40/month for 500 GB. Adding 10,000 provisioned IOPS at $0.065/IOP adds $650/month. If your workload only uses 2,000 IOPS, you're paying $520/month for unused IOPS.

Multi-Volume Strategies

For databases, separate the data volume (high IOPS) from the log volume (high throughput) and the backup volume (cheap capacity). This approach lets you optimize cost and performance independently for each workload component.

Reserved Capacity and Savings Plans

Some cloud providers offer committed-use discounts for block storage. AWS doesn't discount EBS directly, but the EC2 Savings Plans indirectly reduce the cost of attached storage workloads. Azure offers reserved capacity for managed disks with up to 50% savings.

Frequently Asked Questions

• What is the difference between gp3 and io2?

  gp3 is general-purpose SSD storage with 3,000 baseline IOPS. io2 is provisioned-IOPS SSD for latency-sensitive workloads needing up to 64,000 IOPS per volume. io2 costs significantly more but guarantees consistent sub-millisecond latency.

• How do I know how many IOPS I need?

  Monitor your existing volumes for 2–4 weeks. Check the average and peak IOPS consumption. Provision for your 95th percentile peak with 20% headroom. Most web application volumes need 3,000–6,000 IOPS.

• Can I change volume type without downtime?

  AWS allows EBS volume type modification without detaching the volume. The change applies gradually over minutes to hours. Azure requires a stop/deallocate for some tier changes. Always snapshot before modifying.

• What about throughput-optimized (st1/sc1) volumes?

  st1 (throughput-optimized HDD) and sc1 (cold HDD) are much cheaper per GB ($0.045 and $0.015) but offer only 500 and 250 IOPS max. Use them for large sequential workloads like data warehouses and log processing.

• Do snapshots cost extra?

  Yes. EBS snapshots cost $0.05/GB-month for the data stored. Snapshots are incremental—after the first snapshot, only changed blocks are stored. A 500 GB volume with 5% daily change would cost about $1.25/month for a single-day snapshot.

• How does block storage differ from object storage?

  Block storage provides a raw volume that you format with a filesystem and attach to a single instance. Object storage (S3) stores files accessed via HTTP/API. Block storage has lower latency and supports databases; object storage scales infinitely.