Homelab Power & Cost Calculator
Add the gear in your rack to see total draw, daily energy use, and what it costs per month and per year at your electricity rate. There is a UPS runtime estimate at the bottom. Runs in your browser.
- Total draw
- 135 W
- Per day
- 3.24 kWh
- Per month
- $14.79
- Per year
- $177.39
UPS runtime estimate
Rough time on battery at the load above. Enter your UPS battery capacity in watt-hours (Wh). If yours is rated in VA, watt-hours are roughly VA × 0.6 × backup minutes the maker quotes, or check the datasheet.
Real runtime is shorter than the math: battery efficiency drops under heavy load and with age. Treat this as the ceiling, not a guarantee.
Idle watts, not nameplate watts
The number that matters for a 24/7 homelab is idle or typical draw, not the power supply rating on the label. A box with a 550 W PSU might pull 45 W sitting at the desktop. If you have a smart plug or a UPS with a display, read the actual draw and use that. The presets here are rough idle figures for a small NAS, a switch, and a few mini PC nodes.
Power is where homelab choices quietly add up. Spinning disks, a power-hungry CPU, or an old enterprise server can cost more in electricity over a couple of years than the hardware did. That tradeoff is worth running before you buy.
Sizing the storage that draws most of this power? Use the RAID & ZFS calculator. Choosing the platform to run it on? Proxmox vs TrueNAS covers the split.