What It CostsTech, Standby & Unit Calculators
Individually trivial, collectively not — plus the two converters that turn a rating plate into a bill.
Device charging cost
A year of phone charges costs less than one coffee.
Amps to watts calculator
The number the breaker cares about, and the one the bill does.
Gaming PC running cost
The 850 W on the power supply is a ceiling, not a bill.
Standby power cost
Watts nobody notices, running 8,760 hours a year.
TV running cost
Pennies an evening — and the box beneath it may cost more.
Watts to kWh calculator
The plate says watts, the bill says kilowatt-hours. This is the bridge.
Everything in this group is small per hour and matters only because of how many hours there are. A television at 90 W costs about eight cents an evening. The same television across a year, plus the box under it, plus the console beside it, plus everything quietly waiting for a remote, becomes a line on the bill you can actually see.
There is one number here worth measuring rather than estimating: a gaming PC. Its draw depends on what it is doing more than on what it is made of, and the figure printed on the power supply is a maximum rather than a consumption. Everything else in this group is predictable enough that a typical figure is close.
The two converters live here for the same reason. Watts on a rating plate, kilowatt-hours on a bill and amps at the breaker are three ways of describing the same electricity, and the moment you start measuring a device rather than guessing at it, you need to move between them.
Frequently asked questions
Does a gaming PC really cost much to run?
More than people expect, less than the heating. Under load a mid-range build draws 300 to 500 W and a high-end one up to 800, plus 30 to 60 W for the monitor. Four hours a day at 450 W is about 650 kWh a year — the same as a fridge, and a quarter of what a tumble dryer used weekly would cost.
Is standby power worth worrying about?
As one device, no. As a household, it is 30 to 60 W running every hour of every day — 260 to 525 kWh a year for nothing. That is more than most people’s fridge. The fix is not unplugging everything; it is finding the three or four worst offenders, usually a set-top box, a games console not in its low-power mode, and an old AV receiver.
Do modern televisions use less than old ones?
Dramatically. A plasma from 2010 could draw 300 W; a comparable LED today is 60 to 120 W and an OLED somewhere between, depending on how bright the picture is. Screen brightness is the biggest variable — a television in a bright room set to maximum can use half again what the same set uses in the evening.
What about phone chargers left plugged in?
Genuinely negligible now. A modern charger with nothing attached draws well under a watt — pennies a year. The advice to unplug chargers dates from an era of far leakier transformers. Set-top boxes and games consoles are where the standby watts actually are.
How we calculate this
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