# How Reefy estimates cloud cost savings



## What the estimate means

Reefy estimates the shared-cloud compute and storage charges you avoid while
running workloads on hardware you already own. It is a comparison estimate,
not a provider quote, accounting statement, or guarantee of financial savings.

The estimate answers a deliberately narrow question: **what would the
reported CPU, memory, and disk capacity cost under Reefy's stable
shared-cloud comparison rate card for the hours this device was online?**

## Inputs Reefy uses

For each adopted device, Reefy reads:

- logical CPU count reported by Linux;
- installed memory, preferring physical-module information when available;
- total non-removable block-device capacity; and
- completed one-hour online intervals observed by the Reefy service.

GPU capacity, workload utilization, and benchmark performance do not affect
the estimate.

## Shared-cloud comparison rate card

The rate card is intentionally stable so a displayed total does not change
retroactively whenever a provider edits its catalog. It is not described as a
live industry median. The current baseline was reviewed on July 21, 2026.

| Minimum device CPU | Minimum device memory | Compute baseline per month | Included disk |
|---:|---:|---:|---:|
| 1 | 2 GB | $12 | 50 GB |
| 2 | 4 GB | $24 | 80 GB |
| 2 | 8 GB | $48 | 160 GB |
| 4 | 8 GB | $48 | 160 GB |
| 4 | 16 GB | $96 | 320 GB |
| 8 | 32 GB | $192 | 640 GB |
| 16 | 64 GB | $384 | 1,000 GB |
| 32 | 128 GB | $768 | 2,000 GB |
| 48 | 192 GB | $1,152 | 3,000 GB |
| 64 | 256 GB | $1,536 | 4,000 GB |
| 96 | 384 GB | $2,304 | 6,000 GB |
| 128 | 512 GB | $3,072 | 8,000 GB |

Above 128 logical CPUs, the extension is $24 per CPU per month with 64 GB of
included disk per CPU.

Reefy chooses the highest row for which the device meets both the CPU and
memory minimums. A device between rows is matched down, not up. Devices below
the first row use the first row.

Public plan catalogs used to sanity-check the baseline include
[DigitalOcean Droplets](https://www.digitalocean.com/pricing/droplets),
[Akamai Cloud plans](https://techdocs.akamai.com/cloud-computing/docs/compute-instance-plan-types),
[Vultr Cloud Compute](https://www.vultr.com/pricing/),
[Google Cloud Compute Engine](https://cloud.google.com/compute/vm-instance-pricing),
and [Hetzner Cloud](https://www.hetzner.com/cloud/). Their plan shapes,
regions, currencies, discounts, and billing rules differ. Reefy does not
represent the table as a quote from any one provider.

## Storage baseline

Disk beyond the amount included in the matched row adds $0.10 per GB per
month to the comparison rate. Disk at or below the included amount adds
nothing.

For example, a 2 CPU, 4 GB device with 100 GB of disk matches the $24 row,
which includes 80 GB. The remaining 20 GB adds $2 per month, producing a $26
monthly comparison rate.

## Uptime and formula

Only completed online hours count. An online status starts a one-hour timer;
when that hour completes, Reefy confirms that the device is still online
before recording it. Repeated online messages do not add time or reset an
active timer. Partial intervals are discarded, including an interval that is
in progress when the Reefy service restarts.

For every historical device-and-rate period, Reefy calculates:

```text
(completed online hours / 730) x
    (monthly compute baseline + monthly extra-disk baseline)
```

The dashboard total is the sum of those periods. The value 730 is the average
number of hours in a month.

### Worked example

A 3 CPU, 6 GB device matches the 2 CPU, 4 GB row because Reefy rounds down.
With 80 GB of disk and 365 completed online hours:

```text
(365 / 730) x ($24 + $0) = $12 estimated cloud savings
```

## Hardware and rate changes

When CPU, memory, disk, or the comparison rate changes, Reefy closes the old
period and starts a new one. Previously recorded hours retain their historical
rate and are not recalculated against a newer rate card.

## What the estimate excludes

The estimate does not subtract or assign value to:

- hardware purchase, depreciation, resale value, or financing;
- electricity, cooling, internet access, or local networking;
- maintenance time, replacement parts, or support;
- cloud data transfer, public IP, backup, snapshot, or managed-service fees;
- reserved-instance, committed-use, spot, promotional, tax, or currency
  adjustments;
- GPU rental value; or
- differences between a local physical CPU and a provider's virtual CPU.

These exclusions mean the number should be used as a transparent capacity
comparison, not as total cost of ownership.

## Review policy

Reefy reviews the rate card and source links periodically. A material rate-card
change is applied prospectively: new completed hours use the new baseline,
while historical hours keep the rate recorded at the time.