Getting started
What does a home server cost to run 24/7?
What's the realistic monthly cost of running a home server 24/7?
Short answer
What's the realistic monthly cost of running a home server 24/7?
For a typical always-on mini PC plus a small NAS, the ongoing electricity cost is roughly a few dollars a month at normal residential rates — small enough that the hardware you bought dwarfs it for the first year or more. The number only gets large if you run genuinely power-hungry gear (a big workstation, lots of spinning drives, a discrete GPU under load). Modest boxes are cheap to run.
The 24/7 running cost is mostly electricity: a device's power draw in watts, left on all the time, turned into kilowatt-hours and multiplied by what you pay per unit. A watt drawn continuously for a month is roughly three-quarters of a kilowatt-hour, so a low-wattage box left on adds up to very little — the draw, not the fact that it's always on, is what matters.
- ~6-10Wtypical idle draw of a fanless N-series mini PCballpark from published TDPs — see note below
- ~$3-9/morough electricity for a mini PC + small NAS at ~12¢/kWhestimate; varies with your rate and hardware
- Year 1period where hardware cost dwarfs the electricity
A note on these numbers: the figures here are honest ballparks from published power ratings and typical electricity rates, not meter readings from my own rack — I’m measuring the real draw of each box properly and will replace the estimates with actual watts when I have them. Treat them as order-of-magnitude, and measure your own with a plug meter for a number you can trust.
The cost is watts, not hours
People brace for a scary bill because a server runs all day and night, but “always on” isn’t the expensive part — how much it draws while it’s on is. A modern fanless mini PC sips power; leaving something that draws under ten watts on for a whole month costs about as much as a couple of coffees. The always-on framing makes it feel bigger than it is.
Where the bill actually comes from
If your running costs ever feel high, it’s almost always one of three things: a discrete GPU under load, a desktop-class CPU that idles hot, or a lot of spinning drives. Light compute and SSDs are cheap to keep on; heat and platters are what cost. The most effective move is choosing an efficient low-wattage box for the things that must run 24/7, and saving the thirsty hardware for jobs you can turn on only when you need them.
| Setup | Typical draw | Rough $/month* |
|---|---|---|
| Raspberry Pi | ~3-7W | Around a dollar |
| Fanless mini PC | ~6-20W | A few dollars |
| Mini PC + small NAS | ~20-40W | ~$3-9 |
| Big box + GPU + many drives | 50-150W+ | Meaningfully more |
The light, fanless boxes are genuinely cheap to run — a few dollars a month. The one to watch is the powerful box: a big CPU, a GPU, and a stack of drives is the outlier that actually shows up on the bill.
Common questions
Does leaving it on 24/7 make it expensive?
Not by itself — what matters is how many watts it draws, not the hours. A low-wattage box left on all month costs little because the draw is small. The always-on part only becomes expensive when the thing that's always on is power-hungry, like a big CPU under constant load or a shelf of spinning drives.
How do I find my own real number?
Two easy ways: a cheap plug-in energy meter (a Kill A Watt or an energy-monitoring smart plug) reads the actual watts, or if your box is on a UPS, many units report the load in watts on their screen. Multiply the watts by 0.72 to get kWh per month, then by your electricity rate. That's your true figure, not a ballpark.
What's the single biggest cost driver?
A power-hungry component running continuously — most often a discrete GPU under load, a high-wattage desktop CPU, or a large number of spinning hard drives. If your bill worries you, that's where to look. Swapping a thirsty always-on box for an efficient low-wattage one is the biggest lever you have.