Home Server Power Cost Calculator

How the calculation works

The calculator uses idle power for the hours the server is not under load and load power for the active hours you enter. It then converts the weighted daily energy use from watt-hours to kilowatt-hours.

Average watts = ((idle watts × idle hours) + (load watts × load hours)) ÷ 24
Annual kWh = average watts × 24 × 365 ÷ 1,000
Annual cost = annual kWh × electricity rate

For the most useful result, measure whole-system power at the wall. CPU package power does not include memory, storage, networking, conversion losses, or attached USB devices.

What should count as load time?

Include backups, media transcoding, photo indexing, updates, scheduled jobs, and any other period when measured power is clearly above idle. If your server runs a steady workload, enter the same value for idle and load power.

Worked example from our EQi12 measurements

Our tested Beelink EQi12 showed about 12–14W in short idle observations and about 37W during sustained CPU load. Using 14W idle, 37W load, and two load hours per day produces an estimated average of 15.9W and about 139kWh per year. This is an example, not a default for every mini PC: attached drives, power settings, display output, updates, and workload schedules all change the result.

For the underlying seven-state measurements, read the EQi12 power-consumption report. Replacing its watts with your own wall-meter observations gives a more useful budget than copying a review number.

Measure three states before estimating cost

1. Let the operating system settle, then record an idle range rather than one instant.
2. Run the workload that matters—backup, transcode, compile, or database job—and record its typical draw and duration.
3. Measure sleep or shutdown separately if the server will not remain online all day.

What this estimate does not include

Time-of-use tariffs, taxes, UPS conversion loss, external switches, routers, displays, and seasonal electricity pricing are outside the formula. If a UPS powers several devices, measure the complete protected group or allocate its loss conservatively.