How Much Does It Cost to Run a Desktop Computer?
About $107.57 a year — $8.96 a month — for a 200-watt desktop and monitor used 8 hours a day at the 2024 average rate of $0.16/kWh. An hour at the keyboard costs 3.2¢. Almost all of the rest is noise: 87% of the bill is simply the hours you are using it, which is why the power settings people argue about are worth a few dollars and a laptop is worth $81. Set your own wattage, hours and rate below.
The box only — not the number on the power supply, which is a ceiling.
A 27" LED panel is about 40 W; 4K and ultrawide reach 60 W.
Actually at the keyboard. This is the number that bills.
Typical tower draw in use
Desktop computer cost per month
$8.96
56.0 kWh at $0.16/kWh — $107.57 a year, monitor and idle hours included.
Per hour of use
3.2¢
200 W — tower plus monitor
Your hours at the keyboard
87%
of the year's 672 kWh
A laptop instead
$81.06
saved a year — 75% less energy
200 W × 8 h at the keyboard, 100 W × 2 h idle, 3 W × 14 h asleep and 1 W × 0 h off = 1.84kWh a day × $0.16 × 365 = $107.57 a year.
On, signed in, nobody there. Letting it sleep instead saves $11.33 a year.
Suspended to RAM. Lower this and the spare hours become shut-down hours.
Hours a day off
Whatever the other three leave. Still draws 1 W.
The panel, while idle
Draw while asleep
Draw while switched off
"Off" is not zero — the power supply keeps a standby rail alive so the power button works.
Active draw comes from our appliance data: a non-gaming desktop with its monitor is 150–200 W, a gaming build 400–600 W under load. Idle, sleep and off-mode draw are not published per machine and depend on the parts and the power supply — the values here are assumptions, and a plug-in meter will tell you yours. Not sure of your rate? Check average rates by state.
Annual cost at US average rates
Annual cost = watts in each state ÷ 1,000 × hours a day in that state × 365 × price per kWh
A desktop does not have a wattage, it has four — one for each thing it spends the day doing. Add them up over a 24-hour day and the answer for a typical office PC is 1.84 kWh a day, or 672 kWh a year.
Worked example (160 W tower, 40 W monitor, 8 h a day, $0.16/kWh): 200 W × 8 h + 100 W × 2 h idle + 3 W × 14 h asleep = 1.84kWh a day × 365 × $0.16 = $107.57 per year.
Where the year's kWh go
Four states, one day, 8 hours of it spent doing actual work. Read the last column before you change a single power setting.
| State | Hours a day | Draw | kWh a year | Cost a year | Share of the bill |
|---|---|---|---|---|---|
| ActiveAt the keyboard — tower and monitor awake | 8 | 200 W | 584.0 | $93.44 | 86.9% |
| IdleOn, unattended, panel still lit | 2 | 100 W | 73.0 | $11.68 | 10.9% |
| AsleepSuspended to RAM | 14 | 3 W | 15.3 | $2.45 | 2.3% |
| OffThe power supply's standby rail | 0 | 1 W | 0.0 | $0.00 | 0.0% |
| Total | 24 | — | 672.3 | $107.57 | 100% |
Idle, sleep and off-mode draw are not published per machine — 60 W, 3 W and 1 W are assumptions here, not measurements. The active row is not: it comes from the 150–200 W our appliance data gives a desktop and its monitor. This baseline never shuts down, so the off row is zero hours.
Annual cost by machine and rate
Rows are what the tower pulls while you work it. Columns are what a kilowatt-hour costs where you live. Every cell adds the 40 W monitor and assumes the same day: 8 hours of use, 2 idle, 14 asleep.
| Machine | Idaho$0.10/kWh | US average$0.16/kWh | California$0.28/kWh | Hawaii$0.39/kWh |
|---|---|---|---|---|
| Compact office PC110 W tower · 150 W with the monitor | $53.21 | $84.21 | $146.74 | $204.01 |
| Typical desktop160 W tower · 200 W with the monitor | $67.97 | $107.57 | $187.45 | $260.60 |
| Gaming PC, light load400 W tower · 440 W with the monitor | $138.82 | $219.70 | $382.83 | $532.23 |
| Gaming PC, typical load500 W tower · 540 W with the monitor | $168.34 | $266.42 | $464.24 | $645.40 |
| Gaming PC, heavy load600 W tower · 640 W with the monitor | $197.87 | $313.14 | $545.65 | $758.58 |
State rates come from the rates by state page. The gaming rows hold idle draw at the office tower's assumed 60 W, which flatters them — a gaming PC idles nearer 80–150 W, so set that in the calculator if it is yours. Note what the table says about geography: the same desktop costs $260.60 a year in Hawaii and $67.97 in Idaho. Moving house beats every power setting on this page.
Desktop vs laptop energy use
A laptop is a desktop that has to survive on a battery, and every watt it saves is a minute it stays alive unplugged. That design pressure is why it draws about 50 W with its screen already included, while a desktop tower pulls 160 W before you plug a monitor into it. Doing the same 8-hour day of work, the difference over a year is $81.06.
Desktop and monitor
$107.57
a year — 200 W in use, 672 kWh
Laptop, screen included
$26.51
a year — 75% less energy
Laptop + external monitor
$49.87
a year — 54% less energy
“60–70% less” depends on whether you count the monitor
Both of the numbers you see quoted are right, and they are answers to different questions. Against the tower alone, a 50 W laptop uses 69% less than 160 W. Against the desktop as you actually use it — tower plus a 40 W panel, 200 W in total — it uses 75% less, because a laptop brings its own screen. The second comparison is the fair one right up until you plug an external monitor into the laptop, which most people at a desk do. Then the saving falls to $57.70 a year and 54%.
The saving is real, but it will not pay for the laptop
$81.06 a year is the largest number on this page and it is still only $81.06 a year. Buy a laptop because you want to work somewhere other than that desk. Buy the desktop because it is faster, cheaper to repair and easier to upgrade. Electricity is not the deciding argument in either direction — over five years the gap is about $405, which is less than the price difference between the two machines.
Where a gaming PC lands
A gaming PC draws 500 W under load, against 160 W for an office tower — so on the same 8-hour day it costs $266.42 a year rather than $107.57, and that assumes it idles as gently as an office machine, which it does not. It is the one desktop where the wattage genuinely shows up on a bill, and the one where undervolting the GPU and letting it sleep are worth the trouble.
How to reduce PC electricity costs
Here is every lever you have, priced. Each is measured against the same baseline — a 200 W desktop, 8 hours of use, 2 idle, 14 asleep, at $0.16/kWh — and applied on its own.
| Change | Saved a year | Of the bill | What it costs you |
|---|---|---|---|
| Work on a laptop instead | $81.06 | 75% | A different machine — but the only change here that moves the bill by tens of dollars |
| One hour less a day at the keyboard | $11.62 | 11% | An hour of your day; nothing else |
| Let it sleep when you step away | $11.33 | 11% | A few seconds waking it up |
| Blank the display when you step away | $4.67 | 4% | Nothing — but it overlaps with sleeping, below |
| Shut down overnight instead of sleeping | $1.64 | 2% | A cold boot every morning |
Sleeping when idle and blanking the display act on the same 2 idle hours, so they do not add up — if the machine sleeps, the panel is already dark. Sleeping when idle and shutting down overnight act on different hours, so they do: together they save $13.20 a year.
Sleep when you step away — the one setting worth changing
An idling desktop with its screen lit pulls 100 W. Asleep it pulls 3 W. The two hours a day you are signed in but not there are therefore costing $11.68 a year to accomplish nothing, and setting sleep to kick in after ten or fifteen minutes recovers $11.33 of it. That is the whole of PC power management in one sentence. Every other setting is smaller.
Shutting down overnight is worth $1.64 a year
This is the advice everyone repeats, and it is the weakest one here. A sleeping machine draws 3 W; a switched-off one still draws about 1 W, because the power supply keeps a standby rail alive for the power button. Shutting down for all 14 of those hours saves the difference — 3 W less 1 W, for 14 hours, 365 times — which comes to $1.64. Shut down for the boot hygiene if you like. Do not do it for the money, and do not lose sleep over leaving it on. If you want the standby draw to actually stop, the hard switch on the back of the power supply or a switched power strip is what does it.
87% of the bill is you, using the computer
Look again at the breakdown table. The 8 hours you spend at the keyboard are $93.44 of a $107.57 bill. There is no power setting that touches that number, because those are the hours the machine is doing the thing you bought it for. One hour less a day is worth $11.62 a year — more than shutting down every night and blanking the display put together. Which is a roundabout way of saying that a desktop computer is not why your electricity bill is high. See what actually costs money to run, or the room-by-room savings guide, and spend the afternoon on your water heater instead.
Related Guides
Gaming PC Running Cost
500 W under load — the one desktop the bill notices
Cost to Run a Laptop
50 W with the screen included — $26.51 a year
How to Save on Energy Bills
Practical tips by room with savings
Appliances That Drain Power When Off
Why "off" is never really zero
The Cost of Running Appliances 24/7
A PC that never sleeps costs $280 a year
Electricity Rates by State
Find your state's average rate
Frequently Asked Questions
How much electricity does a desktop computer use?
A non-gaming desktop and its monitor draw about 200 W together while you are working — roughly 160 W for the tower and 40 W for a 27" panel. That is 3.2¢ an hour at the US average rate of $0.16/kWh. Used 8 hours a day, left idle for 2 and asleep for the other 14, the machine gets through 1.84 kWh a day, or 672 kWh a year. A gaming PC is a different animal: 400–600 W under load, which on the same day would cost $266.42 a year rather than $107.57.
How much does it cost to run a desktop computer per year?
About $107.57 a year — $8.96 a month — for a 200 W desktop used 8 hours a day at $0.16/kWh. That is 672 kWh. Where you live moves it more than anything you do to the machine: the same PC costs $67.97 a year in Idaho and $260.60 in Hawaii.
Does a desktop use more electricity than a laptop?
Yes, by a lot. A laptop draws about 50 W with its screen included, against 160 W for a desktop tower alone — 69% less — or 75% less once you count the desktop's 40 W monitor, which the laptop does not need. Over a year of the same work that is $26.51 against $107.57, a saving of $81.06 and 75% of the energy. Plug an external monitor into the laptop, as most people do at a desk, and the gap narrows to 54% — $57.70 a year.
Should I shut my PC down at night or put it to sleep?
On electricity alone it barely matters. A sleeping desktop draws around 3 W and a switched-off one still draws about 1 W, so shutting down for 14 hours a night saves roughly $1.64 a year — less than a cup of coffee. The setting that is worth changing is the one for when you step away during the day: letting the machine sleep after a few minutes rather than idling at 100 W saves about $11.33 a year, six times as much. Do both and you save $13.20. Sleep and off-mode draw are not published per machine and depend on your power supply, so both figures are assumptions here; a plug-in meter will tell you yours.
Does a computer use electricity when it is switched off?
Yes — about 1 W. The power supply keeps a standby rail alive so the power button, the clock and wake-on-LAN still work, which is why the back of a PSU has a hard switch. Over a full year of never being used at all, 1 W is 8.8 kWh, or $1.40. It is real, it is on your bill, and it is the smallest number on this page. The hours you spend at the keyboard are 87% of what this machine costs.
How much does it cost to run a PC 24/7?
If it never sleeps and never idles — a home server, a machine left rendering — a 200 W desktop running around the clock costs $280.32 a year at $0.16/kWh, against $107.57 for the same PC on a normal 8-hour day. Tripling the hours roughly triples the bill, because 87% of a desktop's cost is already just the hours it is awake and working.