PBS storage and cost calculator

Estimate how much backup storage your Proxmox fleet will need, and what it costs on Cloud-PBS or self-hosted. Instant recalculation, no signup.

The calculator multiplies your VM count by average VM size, applies a typical 3% change rate per backup over your retention window, then divides by a 6x deduplication ratio to estimate effective storage. It matches that figure to Cloud-PBS pricing and to a representative three-year total cost of self-hosting (hardware, power, bandwidth, sysadmin time).

Your workload

10
50 GB
30 days
Advanced assumptions
3%

Percentage of VM data that changes between two backups. Production web and app workloads typically 2-5%. Database-heavy workloads 5-15%.

6×

PBS content-defined chunking deduplicates across backups. Typical ratios: 4-6x for mixed VMs, 8-12x for homogeneous fleets with slow change rates.

€60/h
3 h

Operational time on the self-hosted PBS host: patching, verify investigations, disk swaps, restore drills. Most fleets sit between 2 and 5 hours per month once steady state is reached.

Estimated backup storage

First full backup

500 GB

Raw data retained

935 GB

Effective (deduplicated)

156 GB

Recommended Cloud-PBS plan

Shared — 250 GB

Three-year cost comparison

Cloud-PBS (managed)

Monthly

€6/mo

3-year total

€216

Includes hardware, patching, monitoring, off-site, support, scaling.

Self-hosted equivalent

Monthly (amortised)

€305/mo

3-year total

€10980

Line items
Hardware (server, disks, 5-year amortisation)
€2100
Rack and power
€1440
Off-site bandwidth
€360
Sysadmin time
€6480
One disk replacement and one restore drill
€600

You save €10764 on Cloud-PBS over three years compared with self-hosting the same workload. Numbers assume steady state and ignore inflation.

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Methodology

  1. Raw first backup: VM count multiplied by average VM size. If you enter a total size directly, that value is used verbatim.
  2. Raw total retained: first backup plus (change rate multiplied by number of retained backups minus one). Backups per retention window depend on frequency.
  3. Effective storage: raw total divided by the deduplication ratio. PBS content-defined chunking deduplicates both across time and across similar VMs.
  4. Recommended plan: smallest Cloud-PBS plan whose capacity ceiling covers effective storage. Shared plans up to 15 TB, above that the Instance tier scales on request.
  5. Cloud-PBS cost: live pricing from our shared and instance tiers. The calculator falls back to the 250 GB entry plan if effective storage is below 250 GB.
  6. Self-hosted cost: hardware amortised over 5 years but used over 3, rack and power at 40 EUR per month, bandwidth at 10 EUR per month, sysadmin rate and hours as configured in advanced settings, plus a one-off incident allowance.

About this calculator

How accurate is the estimate?
Accuracy depends on how representative your inputs are. On the defaults (3% change rate, 6x dedup), the result is usually within 20% of real-world steady-state usage for mixed Proxmox VE fleets. If your workload is heavily database-skewed, bump the change rate to 8-12% and lower the dedup to 4x. If you run homogeneous VMs from a template, drop the change rate to 2% and raise dedup to 10x.
Why set the deduplication ratio to 6x by default?
Six is a conservative middle ground across the Proxmox fleets we operate. Homelabs often see 3-4x because of high heterogeneity. Production fleets with golden images commonly reach 10-15x. Using 6x avoids overpromising when you have not yet measured your own ratio.
Does the self-hosted cost assume I buy new hardware?
Yes, new hardware amortised over five years, used over three. If you already have a spare server, the hardware line becomes zero and managed savings shrink, but sysadmin time remains the dominant cost and still favours managed for most organisations.
Can I export or share the result?
Not yet. A shareable URL that encodes all inputs is on the backlog. In the meantime you can screenshot the comparison or send us your inputs and we will run the numbers alongside you.

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