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Calcrivo

Snapshot Cost Calculator

Price EBS snapshots as the incremental blocks they really are, and compare that with full-size Snapshot Archive copies.

Inputs

GiB
%

Snapshots copy written blocks only, never empty space.

%
snapshots
USD per GB-month
snapshots
USD per GB-month

Monthly Snapshot Cost

$54.90

Standard Snapshot Data Stored

648.0GiB

Standard Snapshot Cost

$32.40

Snapshot Archive Cost

$22.50

Cost If Every Snapshot Were Full Size

$750.00

Amount a Full-size Estimate Overstates

$717.60

Step by step

  1. Values used

    Provisioned volume size = 500 GiB; Share of the volume actually written = 60 %; Blocks changed between snapshots = 4 %; Standard snapshots retained = 30 snapshots; Standard snapshot price = 0.0500 USD per GB-month; Snapshots moved to Snapshot Archive = 6 snapshots; Snapshot Archive price = 0.0125 USD per GB-month

  2. Snapshot Cost

    standard snapshot GiB = used GiB + (snapshots − 1) x changed GiB; archive GiB = archived snapshots x used GiB, because archived copies are full.

  3. Monthly Snapshot Cost

    = 54.90

  4. Standard Snapshot Data Stored

    = 648.0 GiB

  5. Standard Snapshot Cost

    = 32.40

  6. Snapshot Archive Cost

    = 22.50

  7. Cost If Every Snapshot Were Full Size

    = 750.00

  8. Amount a Full-size Estimate Overstates

    = 717.60

How it works

Only the first EBS snapshot of a volume is anything like full size; every later one stores just the blocks that changed, and all of them share the unchanged blocks, so thirty daily snapshots cost far less than thirty copies. Snapshot Archive inverts that: it is a much cheaper per-GB rate but stores a full, independent copy with a 90-day minimum, so it only wins for snapshots you keep for a long time and rarely restore. All rates are user-supplied list prices to confirm on the AWS EBS pricing page for your region. Budgets built on volume size times snapshot count routinely overstate snapshot spend by an order of magnitude, and the same misunderstanding is why teams archive snapshots that were cheaper left incremental.

Formula

Snapshot Cost

standard snapshot GiB = used GiB + (snapshots − 1) x changed GiB; archive GiB = archived snapshots x used GiB, because archived copies are full.

used GiB
Written blocks on the volume, the only blocks a snapshot copies
changed GiB
Blocks modified between consecutive snapshots

Frequently Asked Questions

How is Snapshot Cost calculated?

standard snapshot GiB = used GiB + (snapshots − 1) x changed GiB; archive GiB = archived snapshots x used GiB, because archived copies are full. Only the first EBS snapshot of a volume is anything like full size; every later one stores just the blocks that changed, and all of them share the unchanged blocks, so thirty daily snapshots cost far less than thirty copies. Snapshot Archive inverts that: it is a much cheaper per-GB rate but stores a full, independent copy with a 90-day minimum, so it only wins for snapshots you keep for a long time and rarely restore. All rates are user-supplied list prices to confirm on the AWS EBS pricing page for your region.

Why does Snapshot Cost matter?

Budgets built on volume size times snapshot count routinely overstate snapshot spend by an order of magnitude, and the same misunderstanding is why teams archive snapshots that were cheaper left incremental.

What values do I need to enter?

This calculator takes 7 inputs: Provisioned volume size, Share of the volume actually written, Blocks changed between snapshots, Standard snapshots retained, Standard snapshot price, Snapshots moved to Snapshot Archive, Snapshot Archive 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.

Does deleting a snapshot free its full size?

No. Deleting a snapshot only frees blocks no remaining snapshot references, so removing one snapshot from the middle of a chain often reclaims almost nothing.

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