A Free Calculator · Your Devices, Your Rate · Updated 2026
What is vampire power costing you every year?
Standby power — the electricity your devices sip 24/7 while switched off or idle — is
invisible on your bill but real in your total. Tick the always-plugged gadgets you own,
enter your electricity rate, and the calculator returns the annual, monthly, and daily
cost, plus the total watts you're drawing around the clock. Every formula is shown, and
no number is presented as your own measured fact.
Read this first
The standby wattages built into this tool are typical figures that vary by model,
age, and settings — they are not your device's measured draw. The only way to know your own
is a plug-in power meter that reads watts at the outlet. The good news: the fix is cheap.
Advanced (smart) power strips, plain switchable strips, and simply unplugging idle gear cost
little or nothing. But some devices are meant to stay on — your modem and router keep your
internet alive, and a DVR has to stay powered to record — so this is about cutting idle waste,
not unplugging everything.
Set how many of each device you leave plugged in (most start at zero — a few common ones are pre-filled). Add anything we missed in the custom row, enter your electricity rate, and the cost updates as you go.
Devices left plugged in
Device — typical standby drawHow many
Your electricity rate
$/ kWh
From your electric bill. The U.S. residential average runs around 16–17¢/kWh but varies widely by state and season — ENERGY STAR and your utility have local figures.
Standby power costs you
Per year
Per month
Energy per year
Total standby draw
The formulas, in full
Nothing here is a black box. These are the exact calculations the tool runs — the same
arithmetic you could do on paper. The only judgment calls are the device quantities and
the rate you supply; the standby wattages are typical approximations you can confirm with
a meter.
A quick reference for how a single device's standby draw turns into a yearly bill. The
cost column assumes the device runs 24 hours a day, 365 days a year, at $0.17/kWh — the
same arithmetic as the formulas above. All wattages are typical and approximate; your own
device may draw more or less.
Device
Typical standby watts
Cost / yr at $0.17 (24/7)
Cable/satellite box with DVR
~28 W
~$41.68
Cable/satellite box (no DVR)
~18 W
~$26.79
Game console (instant-on)
~10 W
~$14.89
Modem + router (always on)
~10 W
~$14.89
Desktop PC (sleep)
~5 W
~$7.44
Soundbar / AV receiver (standby)
~5 W
~$7.44
Laptop charger (idle)
~4 W
~$5.95
Microwave (clock)
~3 W
~$4.47
TV (standby)
~2 W
~$2.98
Phone charger (no phone)
~0.3 W
~$0.45
Standby wattages are typical approximations — varies by model; based on LBNL standby-power
data. Cost per year is computed as watts ÷ 1000 × 24 × 365 × $0.17, rounded to the nearest
cent. A device's real draw depends on its age, settings (instant-on vs. full sleep), and
whether it's actively updating; confirm with a plug-in power meter.
Why a few watts turns into real money
Phantom load is a story about time, not power. Understanding which devices dominate — and
which are worth leaving alone — is what turns this from a curiosity into a few cut items
on your bill.
Small watts, big hours — 24/7 is what makes it add up
A single watt left on continuously costs about $1.49 a year at $0.17/kWh — trivial on its own. But standby loads never switch off: they draw every hour of every day, all year. That's 8,760 hours of multiplication. A handful of devices at a few watts each, running constantly, quietly compounds into a $50–$200 line you never see itemized. The power is small; the runtime is enormous, and runtime is what the bill charges for.
The worst offenders
The heaviest standby draws are entertainment and networking gear that stays half-awake on purpose. Cable and satellite boxes with built-in DVRs lead the pack — they keep recording schedules and program guides live and can draw 20–30+ watts around the clock. Game consoles left in instant-on or quick-resume mode draw roughly 10 watts so they can wake instantly and pull updates. Older AV receivers and soundbars can also waste several watts in standby. These are the devices that justify a power strip.
What's worth cutting vs. leaving on
Don't unplug your modem and router — you'll lose internet, and they draw relatively little for what they do. Leave the refrigerator and freezer alone; they aren't standby loads at all, they run to keep food safe. And don't kill a DVR mid-recording. Do cut the idle entertainment center: a TV, game console, soundbar, and streaming box that sit dark most of the day can share one switchable strip. Target the high-hour idle draws and ignore the rounding-error ones like phone chargers.
How to cut your phantom load
You don't need to crawl behind the TV every night. A few one-time setups do nearly all of
the work and then run themselves.
Find your always-on devices
Walk the house and note anything that shows a clock, a standby light, a network indicator, or that you never fully power off — TVs, cable boxes, consoles, AV gear, printers, smart speakers, chargers. Those are your phantom loads. The calculator above gives you a fast way to total them up.
Group entertainment gear on one switchable strip
Put the TV, game console, soundbar, and streaming box on a single power strip with a switch. Flip it off when you're done for the night and the whole cluster stops drawing standby power at once — no per-device unplugging.
Turn off console instant-on
Dig into your game console's settings and disable instant-on, quick-start, or quick-resume. The console will take a little longer to wake, but it sleeps fully instead of drawing ~10 watts around the clock waiting to download updates.
Use smart plugs on seasonal or idle gear
For a printer, a guest-room TV, holiday electronics, or anything used occasionally, put it on a smart plug you can schedule or switch from your phone. It cuts the standby draw on your terms without you remembering to unplug it.
Measure with a plug-in power meter
To replace these typical figures with your home's real numbers, plug a cheap inline power meter between the outlet and a suspect device and read the watts. Measure the biggest suspected offenders first — that's where any real savings live, and it tells you which fights are worth picking.
Where to buy
Got your numbers? Here's where to pick up what you need:
The handful of words that come up when you start chasing standby power — in plain English.
Phantom load (standby load)
The electricity a device draws while it is switched off or idle but still plugged in — to keep a clock running, listen for a remote, stay on the network, or simply because its power supply never fully shuts off. Also called idle load. Small per device (often 1–30 watts), but it runs 24/7, so it adds up over a year.
Vampire power
A common nickname for phantom load — the power "drained" by devices that appear to be off. Same concept; the dramatic name just captures that it's invisible and continuous.
Watt (W)
A unit of power — the rate at which a device uses electricity at a given moment. A standby light might pull 2 watts; a DVR cable box might pull 28. Power (watts) sustained over time produces energy (kWh), which is what the utility bills.
Kilowatt-hour (kWh)
A unit of energy — one kilowatt (1,000 watts) of power drawn for one hour. It's the unit your utility bills you in, at a price per kWh. A device drawing 10 watts continuously for a year uses 10 ÷ 1000 × 24 × 365 ≈ 87.6 kWh.
Advanced power strip (APS)
A power strip with built-in logic that cuts power to peripheral devices when a "master" device goes to sleep — for example, switching off the soundbar, console, and streaming box when the TV turns off. It automates the job of unplugging idle phantom loads.
Smart plug
A plug that sits between the outlet and a device and can be switched or scheduled remotely — usually from a phone app or voice assistant. Useful for cutting standby power on seasonal or rarely used gear without physically unplugging it.
Instant-on (quick-start)
A standby mode — common on game consoles and some TVs — that keeps the device partly awake so it can turn on almost immediately and download updates in the background. Convenient, but it raises standby draw (a console can pull ~10 watts) compared with a full power-off.
Frequently asked
For a typical U.S. home, standby (phantom) power is often estimated at roughly $50 to $200 per year, depending on how many devices you leave plugged in and your electricity rate. The reason it adds up is time, not power: a device drawing only a few watts does so 24 hours a day, 365 days a year. A single cable box with a DVR drawing about 28 watts costs roughly $42 a year at $0.17/kWh — and that's just one device. Add a game console in instant-on, an always-on modem and router, a couple of TVs in standby, and a few chargers, and a hundred-dollar-plus total is easy to reach. The calculator above lets you tick the devices you actually leave plugged in and enter your own rate.
Phantom load — also called vampire power, standby power, or idle load — is the electricity a device draws while it's switched off or idle but still plugged in. Anything with a clock, a remote-control receiver, a standby light, a network connection, or an external power brick is usually drawing something around the clock: a TV waiting for the remote, a cable box updating its guide, a console in instant-on mode, a microwave showing the time, a charger left in the wall. Each draw is small — often 1 to 30 watts — but because it runs continuously, the kWh accumulate over a year. The only way to know your home's exact phantom load is to measure each device with a plug-in power meter; the figures here are typical approximations.
The worst offenders are usually entertainment and networking gear that stays partly awake to be instantly responsive. Cable and satellite boxes with built-in DVRs are among the heaviest — they keep recording and updating program guides and can draw 20 to 30+ watts continuously. Game consoles left in instant-on draw around 10 watts so they can wake quickly and download updates. Always-on modems and routers draw roughly 10 watts combined by design. Older AV receivers and soundbars can also draw several watts in standby. By contrast, a phone charger with nothing plugged in draws a fraction of a watt — real, but tiny. Use the calculator above to see which devices dominate your own total.
No — and trying to is what makes people give up. Some devices are meant to stay on, and unplugging them causes more hassle than it saves. Don't unplug your modem and router (you'll lose internet, and they sip relatively little), your refrigerator or freezer (they're not standby loads — they run to keep food safe), or a DVR mid-recording. Instead, target the idle entertainment center: a TV, game console, soundbar, and streaming box that sit dark for most of the day can share one switchable power strip you flip off at night. The goal is to cut the easy, high-hour idle draws without disrupting the devices that genuinely need to stay powered.
A little, but far less than the old myth suggests. A modern phone charger left plugged in with no phone attached typically draws only a fraction of a watt — on the order of 0.1 to 0.5 watts. Over a year that's a few cents to maybe a dollar per charger, not a meaningful part of your bill. Older or cheap chargers and large laptop power bricks draw more (a laptop charger left idle can pull a few watts), so those are worth unplugging or switching off. The honest takeaway: chasing every phone charger is mostly symbolic; your time is better spent on the cable box, console, and AV gear that draw ten to thirty times as much around the clock.
The cheap, low-effort fixes do most of the work. Group your idle entertainment gear — TV, game console, soundbar, streaming box — onto one power strip and switch it off when you're done for the night; an advanced (smart) power strip can do this automatically by sensing when the main device sleeps and cutting power to the peripherals. Turn off your console's instant-on mode in its settings so it sleeps fully. Put seasonal or rarely used gear (a printer, a second TV, holiday electronics) on smart plugs you can schedule. Leave the things that must stay on — modem, router, fridge — alone. To confirm what's worth your effort, measure suspect devices with an inexpensive plug-in power meter and act on the biggest draws.
Common mistakes with this calculator
Phantom load estimates are often off because people focus on the wrong devices or misclassify what counts as standby draw.
Chasing phone chargers while ignoring the cable box
A typical phone charger with no phone plugged in draws 0.1–0.3 W. A cable or satellite DVR with a hard drive runs 15–30 W continuously — even when you think it's "off" — because it's recording scheduled programs and downloading guide data. Prioritizing chargers over the entertainment stack is the most common reason people do this exercise and then see a smaller-than-expected bill change. Sort by watts first, then act on the highest draws. Source: LBNL standby power database.
Including appliances that aren't actually standby loads
Phantom load applies to devices that draw power while appearing off or idle. A refrigerator, a chest freezer, or a fish tank pump are not standby loads — they are actively running appliances doing a job. Including them in a phantom-load estimate conflates two different problems. Those belong in an appliance-running-cost calculation, not here.
Entering quantity 1 for devices you own multiples of
If you have three TVs, two game consoles, or four phone chargers, the quantity field matters. A single TV might add $10/year in standby; three TVs add $30. The calculator multiplies watts × quantity × hours — undercounting quantity directly undercounts your total.
Treating the typical standby wattage as your device's actual draw
Standby power varies widely by manufacturer, age, and settings — sometimes by 10× for the same device category. The figures in this calculator are representative averages, not your device's measured draw. The only way to know your actual number is to measure it with an inexpensive plug-in power meter (such as a Kill A Watt). Measure once for any device you're seriously trying to reduce. Source: LBNL standby power database.