Tools / Homelab power and cost calculator
Homelab power and electricity cost calculator
Add up your servers, NAS, switches and access points to see what your homelab draws and what it costs to run each month and each year. Free, no sign-up.
Your devices
This is an example. Change anything to make it yours.
For each device enter its name, the watts it draws on average (a plug-in power meter gives the best number), how many you have, and the hours a day it runs.
The price and currency started from a typical rate for US, picked from your browser's language. Use the price on your own bill.
What it costs
- Power draw
- 104 W
- Per day
- $0.42
- Per month
- $12.91
- Per year
- $154.88
- Energy per year
- 911 kWh
- CO2 per year
- 337.1 kg
| Device | Per month | Share |
|---|---|---|
| Mini PC (N100 class) | $2.98 | 23.1% |
| NAS, 4 bay, drives spinning | $4.34 | 33.7% |
| Gigabit switch, 24 port | $2.48 | 19.2% |
| Router or firewall appliance | $1.86 | 14.4% |
| Wi-Fi access point | $1.24 | 9.6% |
Share or keep this result
Paste the link into a forum post or an article and it turns into a card with your numbers on it. The numbers are worked out from the link, so they always match this page.
Sign in to save results and come back to them later.
How the cost is worked out
For each device, the calculator multiplies its average draw in watts by how many you have and the hours a day it runs, then divides by 1,000 to get kilowatt hours (kWh). Your cooling multiplier is applied on top, and the total is multiplied by your electricity price.
A worked example: a 12 W mini PC running around the clock uses 12 × 24 ÷ 1,000 = 0.288 kWh a day, about 105 kWh a year. At 0.17 per kWh that is roughly 17.87 a year. A single 120 W server left on all year is ten times that.
To cut the bill, look at the share column first: one or two devices usually account for most of it. Replacing an idle rack server with a mini PC is often the biggest saving.
Questions about this tool
How do I work out what my homelab costs to run?
Multiply each device's average draw in watts by the hours it runs, divide by 1,000 to get kilowatt hours, then multiply by your electricity price per kWh. This calculator does that for every device and adds them up for a day, a month and a year.
What wattage should I enter for a device?
Use the average draw, not the label on the power supply. A plug-in power meter gives the best number. Without one, the presets are typical averages for common gear, and a server that sits mostly idle draws far less than one running at full load.
What is the cooling multiplier?
Heat from your gear has to go somewhere, and in a closet or a room with air conditioning that costs more electricity. A multiplier of 1.0 counts only the devices. 1.2 to 1.5 is a fair guess if you cool the space.
Where do the starting price and emission factor come from?
They are rough national averages picked from the language setting in your browser, only to save you typing. Your electricity bill has your real price per kWh, and you should use that.
Is my data stored?
Not unless you are signed in and choose to save a result. The numbers live in the address of the page, so you can bookmark it or paste it into a forum post.
Save your results and join the community
Create a free account to keep what you work out, and to ask other homelab builders about your setup.