How Much Does It Cost to Run a Laptop?
About 7.3¢ a day — $2.21 a month, $26.51 a year — for a 50-watt laptop used 8 hours a day at the 2024 average rate of $0.16/kWh. An hour at the keyboard costs 0.8¢. The number printed on your charger has almost nothing to do with it: across a full day a 50 W laptop averages 18.9 W, or 29% of what a 65 W brick says. Set your own wattage, hours and rate below.
The machine, screen included — not the number on the charger.
Lid open, actually working. This is the number that bills.
Printed on the brick. It changes nothing below — see why.
Typical laptop draw in use
Common charger ratings
Laptop energy cost per day
7.3¢
0.454 kWh a day at $0.16/kWh — $2.21 a month and $26.51 a year.
Per hour of use
0.8¢
50 W while you work
Per month
$2.21
13.8 kWh
Saved vs a desktop
$81.06
a year — 75% less energy
50 W × 8 h in use, 20 W × 2 h idle, 1 W × 14 h asleep and 0.5 W × 0 h off = 0.454 kWh a day × $0.16 = 7.3¢ a day, or $26.51 a year.
Your 65 W charger is not drawing 65 W
At the keyboard it pulls 50 W, or 77% of the brick's rating. Averaged over all 24 hours — 8 in use, 2 idle, 14 asleep — it pulls 18.9 W, which is 29% of what the label says. The rating is the peak the charger can push into an empty battery while the chip is flat out, and it is reached for minutes, not hours.
Lid open, signed in, nobody there.
Lid closed. Lower this and the spare hours become shut-down hours.
Hours a day off
Whatever the other three leave. Still draws 0.5 W.
Not zero while the charger is in the wall.
The desk it sits on
Would unplugging it save anything?
No — it costs about $2.86 a year more.
Working on battery does not make the energy free; it moves it. You pay the wall for it at the next recharge, plus whatever the round trip through the cell loses on the way — assumed here at 90%.
Draw in use comes from our appliance data: a laptop plugged in and working is 30–60 W, and even a gaming laptop under load rarely exceeds 180 W. Idle, sleep and off-mode draw are not published per machine — those three are assumptions, and a plug-in meter will tell you yours. The desktop this compares against is the 160 W tower and 40 W monitor billed on the desktop computer page, worked the same hours. Not sure of your rate? Check average rates by state.
How much electricity does a laptop use?
30–60 watts plugged in and working, screen included.
That is the whole answer, and it is a small number because a laptop is a machine designed around a battery: every watt it saves is a minute it survives unplugged. A 50 W machine costs 0.8¢ an hour to use, which over 8 hours at the keyboard is 0.454 kWh, or 166 kWh a year.
Worked example (50 W, 8 h a day, $0.16/kWh): 50 W × 8 h + 20 W × 2 h idle + 1 W × 14 h asleep = 0.454 kWh a day × $0.16 = 7.3¢ a day, or $26.51 a year.
The number on your charger is a ceiling, not a rate
This is where most answers to this question go wrong. A 65 W brick can push 65 W, and it does — into a flat battery, while the processor is pinned, for as long as that lasts. At the keyboard with a full battery your 50 W laptop is asking for 77% of that. Averaged over all 24 hours it asks for 18.9 W, which is 29% of the label.
| What it's doing | Draw | Cost per hour | If it did only this, all year |
|---|---|---|---|
| In useLid open, plugged in, working | 50 W | 0.8¢ | $70.08 |
| IdleOn, signed in, nobody there | 20 W | 0.3¢ | $28.03 |
| AsleepLid closed, suspended to RAM | 1 W | <0.1¢ | $1.40 |
| OffShut down, charger still in the wall | 0.5 W | <0.1¢ | $0.70 |
| Charging an empty battery under loadUp to the charger's rating — 65 W on this brick | 65 W | 1.0¢ | — reached for minutes, not hours |
Only the first row comes from measured data: our appliance table puts a working laptop at 30–60 W. Idle, sleep and off-mode draw are not published per machine, so 20 W, 1 W and 0.5 W are assumptions here — a plug-in meter will tell you yours. Your real day is a mixture of these rows, not any one of them, which is what the calculator adds up.
Annual cost by laptop and rate
Rows are what the machine pulls while you work it. Columns are what a kilowatt-hour costs where you live. Every cell assumes the same day: 8 hours of use, 2 idle, 14 asleep, no external monitor.
| Laptop | Idaho$0.10/kWh | US average$0.16/kWh | California$0.28/kWh | Hawaii$0.39/kWh |
|---|---|---|---|---|
| Ultrabook or Chromebook30 W in use | $10.85 | $17.17 | $29.92 | $41.59 |
| Typical laptop50 W in use | $16.75 | $26.51 | $46.20 | $64.23 |
| 16-inch or workstation60 W in use | $19.71 | $31.19 | $54.34 | $75.55 |
| Gaming laptop, under load180 W in use | $55.13 | $87.25 | $152.03 | $211.36 |
State rates come from the rates by state page. The gaming laptop row holds idle draw at the office machine's assumed 20 W, which flatters it. Read the table both ways. The same laptop costs $64.23 a year in Hawaii and $16.75 in Idaho — a $47.48 spread you can do nothing about. Swapping a typical laptop for a gaming one costs $60.74 a year at the US average, which is the wider gap of the two. Which machine you carry moves this bill more than which state you carry it in.
Laptop vs desktop energy cost comparison
Worked the same 8-hour day, a laptop costs $26.51 a year and a desktop and its monitor cost $107.57. The laptop wins by $81.06 — until you plug a monitor into it.
Laptop, screen included
$26.51
a year — 50 W in use, 166 kWh
Laptop + external monitor
$49.87
a year — 90 W in use
Desktop and monitor
$107.57
a year — 200 W in use
The monitor next to your laptop costs $23.36 a year
That is 88% of what the laptop itself costs, from a device you probably do not think of as an appliance. A 27" panel draws 40 W whenever it is lit, and a laptop already has a screen — so the second one is pure addition. It is the reason a laptop's advantage over a desktop collapses from 75% to 54% the moment you dock it, and the reason the largest saving available to a laptop owner is not a power setting at all.
“60–70% less” depends on what you are counting
Both figures you see quoted are right; they answer different questions. Against a desktop tower on its own, a 50 W laptop uses 69% less than 160 W. Against the desktop as it is actually used — tower plus a 40 W panel, 200 W in total — it uses 75% less, because the laptop brings its own screen. Dock the laptop to that same panel and the honest figure is 54%, worth $57.70 a year rather than $81.06.
Electricity is not why you should choose one
$81.06 a year is the largest saving on this page, and it is still only $81.06 a year — about $6.75 a month, and $405 over five years of owning the thing. Real money, and still not the reason to pick one. Buy the laptop because you want to work somewhere other than that desk. Buy the desktop because it is faster for the money and easier to repair. The same reasoning applies further up the range: a gaming laptop under load pulls 180 W where a gaming PC pulls 500 W, and the machine you enjoy using is still the right one.
Tips to reduce laptop energy use
Every lever you have, priced, and applied one at a time to the same day: a 50 W laptop, 8 hours of use, 2 idle, 14 asleep, at $0.16/kWh. The first row assumes you have docked it to an external monitor; the rest do not. The last row is negative, and that is not a typo.
| Change | Saved a year | Of that setup's bill | What it costs you |
|---|---|---|---|
| Unplug the external monitor when you don't need it | $23.36 | 47% | A smaller screen — and it is the only change here that moves the bill by more than a few dollars |
| One hour less a day at the keyboard | $2.86 | 11% | An hour of your day; nothing else |
| Close the lid when you step away | $2.22 | 8% | A second to wake it up |
| Shut down overnight instead of sleeping | $0.41 | 2% | A cold boot every morning |
| Run it on battery and recharge instead of leaving it plugged in | −$2.86 | −11% | It costs more, not less — the wall pays for the recharge, and the cell loses a little |
Each percentage is of the bill for the setup that row changes: the monitor row against a docked laptop's $49.87 a year, every other row against the bare laptop's $26.51. The three settings do not simply add up — closing the lid turns idle hours into sleeping hours, which changes how many hours are left for shutting down to act on. Do all three and you save $5.58 a year, which is the whole of laptop power management, priced.
Unplugging it does not save electricity — it costs about $2.86 a year
This is the most common piece of laptop energy advice and it is backwards. Running on battery does not make the work free; it borrows the energy from a cell that the wall has to refill later. The refill is not perfectly efficient — a lithium-ion pack and its charging circuit give back somewhere around 90% of what they take in, though this is not published per machine — so a year of working on battery and recharging costs about $2.86 more than a year of working plugged in, and somewhere between $1.35 and $4.53 if that round trip is as good as 95% or as bad as 85%. Plug it in where it suits you. What unplugging is genuinely good for is the battery's lifespan, which is a different argument with different evidence.
Turn the brightness down — but we will not pretend to know what it saves
The display is the single largest consumer inside a laptop, so dimming it is the one setting that moves the 50 W figure at the top of this page rather than nibbling at the hours around it. What we will not do is put a dollar figure on it: the split between screen, chip and everything else is not published per machine, and it varies with the panel. If you want your own number, set the wattage box in the calculator above to what a plug-in meter reads at your usual brightness, then read it again at half. That is the only honest way to price this one.
No power setting on a laptop is worth more than $2.22 a year
Closing the lid when you step away saves $2.22. Shutting down overnight instead of sleeping saves $0.41 — an hour of sleep costs <0.1¢, so there is nothing there to recover. Working an hour less each day saves $2.86, which beats both of those settings put together ($2.63). A laptop is, on the evidence of this page, not why your electricity bill is high: at $26.51 a year it is one of the cheapest things you plug in. 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
Cost to Run a Desktop Computer
$107.57 a year — the machine on the other side of this comparison
How to Save on Energy Bills
Practical tips by room with savings
Cost to Run a Gaming PC
500 W under load — the one computer the bill notices
Computer Monitor Running Cost
The 40 W panel that costs $23.36 a year
Appliances That Drain Power When Off
Why a charger in the wall is never quite zero
Electricity Rates by State
Find your state's average rate
Frequently Asked Questions
How much electricity does a laptop use?
A laptop plugged in and working draws about 30–60 watts, screen included — call it 50 W for a typical machine. That is 0.8¢ 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, it gets through 0.454 kWh a day, or 166 kWh a year. Even a gaming laptop under load rarely exceeds 180 W, which on the same day would come to $87.25 a year rather than $26.51.
What is a laptop's energy cost per day?
About 7.3¢ a day — 0.454 kWh at $0.16/kWh — for a 50 W laptop used 8 hours. Over a month that is $2.21 and over a year $26.51. Where you live moves that figure further than any power setting on the machine: the same laptop costs $16.75 a year in Idaho and $64.23 in Hawaii, while closing the lid when you step away is worth $2.22.
Does a 65 W charger use 65 watts?
No. The number on the brick is the most it can deliver — into an empty battery, with the chip flat out — not the rate it runs at. A 50 W laptop at the keyboard is drawing 77% of a 65 W charger's rating, and averaged across a whole day of 8 hours' use, 2 idle and 14 asleep it draws 18.9 W — 29% of the label. Once the battery is full the charger stops charging it, so the wall only pays for what the machine is using.
Does leaving a laptop plugged in all the time use more electricity?
Slightly less, in fact. Working on battery does not make the energy free, it moves it: the wall pays for it at the next recharge, and the round trip through the cell gives back a little less than it took. If every one of your working hours ran off the battery you would pay about $2.86 a year more than leaving it plugged in — $1.35 to $4.53 depending on how efficient that round trip is, which is not published per machine. Plug it in where it suits you. Neither answer is worth changing your habits over.
How much electricity does a laptop use compared with a desktop?
A laptop draws 50 W with its screen already included, against 160 W for a desktop tower on its own — 69% less — or 75% less once you count the desktop's 40 W monitor, which a laptop does not need. Over a year of the same 8-hour days that is $26.51 against $107.57, a saving of $81.06 and 75% of the energy. Plug an external monitor into the laptop and the saving falls to $57.70 — 54%.
How much does it cost to run a laptop 24/7?
A 50 W laptop that never sleeps costs $70.08 a year at $0.16/kWh — 438 kWh — against $26.51 for the same machine on a normal 8-hour day. That is the ceiling: a laptop left running every hour of the year, doing something, still costs less than a desktop worked 8 hours a day.
Does a laptop use electricity when it is switched off?
A little. Shut down with the charger still in the wall, a laptop and its brick draw around 0.5 W between them — 4.4 kWh over a full year, or $0.70. Asleep with the lid closed it draws about 1 W. Both are assumptions rather than published figures, and both are the smallest numbers on this page. Pulling the charger out of the wall recovers them; it will not recover enough to notice.