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EC2 AMI Storage Calculator

Cost AMI generations as incremental EBS snapshots across regions and see how much block-level dedupe saves.

About EC2 AMI Storage Calculator

EBS snapshots are incremental at block level within a region, so the second and later generations of an AMI only bill for blocks that actually changed — a 30 GB image rebuilt weekly with 6% churn costs far less than 12 full copies. Cross-region copies break the chain: the first copy into each region is a full baseline, which is why the region count multiplies the whole figure rather than adding a delta. Retention is nearly free while churn is low and expensive the moment a build rewrites most of the filesystem, so the change rate — not the generation count — is the lever that decides whether an image pipeline is cheap.

Formula

EC2 AMI Storage

billable GB per region = first image GB + (generations − 1) × changed GB; total = that × regions.

delta
Blocks rewritten between builds, the only new data stored
generations
Images kept by your lifecycle policy
regions
Each destination region starts its own full baseline

Worked example

With the default values below, EC2 AMI Storage Calculator returns Monthly Snapshot Cost of $7.47. Change any input above and every figure here is recalculated in your browser.

Inputs used

Used data in the first imageaccepts 0–16,384 GB
30 GB
Blocks changed between buildsaccepts 0–100 %
6 %
Image generations retainedaccepts 1–500 images
12 images
Regions the image is copied toaccepts 1–30 regions
3 regions
Snapshot price per GB-monthminimum 0 USD/GB
0.05 USD/GB

Results

Monthly Snapshot Cost
$7.47
Billable Snapshot Storage
149.4 GB
Billable Storage in Bytes
139.14 GiB
Saved by Incremental Storage
930.6 GB
Effective Dedupe Ratio
7.23 x
Annual Snapshot Cost
$89.64

Step by step

  1. 1Values used
  2. 2EC2 AMI Storage
  3. 3Monthly Snapshot Cost= 7.47
  4. 4Billable Snapshot Storage= 149.4 GB
  5. 5Billable Storage in Bytes= 149,400,000,000.00
  6. 6Saved by Incremental Storage= 930.6 GB
  7. 7Effective Dedupe Ratio= 7.23 x
  8. 8Annual Snapshot Cost= 89.64

Assumptions and limits

  • The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges 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 EC2 AMI Storage calculated?

billable GB per region = first image GB + (generations − 1) × changed GB; total = that × regions. EBS snapshots are incremental at block level within a region, so the second and later generations of an AMI only bill for blocks that actually changed — a 30 GB image rebuilt weekly with 6% churn costs far less than 12 full copies. Cross-region copies break the chain: the first copy into each region is a full baseline, which is why the region count multiplies the whole figure rather than adding a delta.

Why does EC2 AMI Storage matter?

Retention is nearly free while churn is low and expensive the moment a build rewrites most of the filesystem, so the change rate — not the generation count — is the lever that decides whether an image pipeline is cheap.

What values do I need to enter?

This calculator takes 5 inputs: Used data in the first image, Blocks changed between builds, Image generations retained, Regions the image is copied to, Snapshot price per GB-month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Does deregistering an AMI delete the storage?

No. Deregistering removes the image but leaves the backing snapshots, which keep billing. Lifecycle policies must delete the snapshots as well, and this is one of the most common sources of quiet, long-lived EBS spend.

Related Calculators

EC2 AMI Storage Calculator – Calculate Monthly Snapshot Cost