Computers & Laptops

PC Electricity Cost Calculator

What a desktop costs to run per day, month and year, at your own electricity rate.

6 inputs Free, no sign-up

Your figures

Measured with a plug-in energy meter if you can. The power supply's rating is a ceiling rather than a reading - most machines draw well under it, and this page will not assume a figure.

Use fewer for something you only run at weekends.

Rupees per unit (kWh), from your own bill. Tariffs differ by state, by connection and by how much you use, so this is the figure the result is most sensitive to.

Try an example

Result

Your result

Enter your figures and the result appears here.

Estimates only. Rates, fees and specifications change. Confirm against the official source before you rely on a figure — see our disclaimer.

About this calculator

A computer's running cost is its wattage, its hours and your tariff. The wattage is the part people guess at, and it is the part the answer is most sensitive to.

A plug-in energy meter between the wall and the machine settles it in a minute, and is worth more than any estimate: a desktop at idle and the same desktop under load are often three times apart.

How to use this calculator

  1. Measure the machine's draw with a plug-in energy meter, or use a figure you trust.
  2. Enter how many hours a day it runs, and how many days a month.
  3. Enter your electricity rate from your own bill.

Not sure what the components add up to? The PC power calculator gives the worst case, which is higher than the everyday figure.

The formula

Energy a day  = Power / 1000 x Hours a day
Cost a month  = Energy a day x Days a month x Rate per unit

A "unit" on an Indian electricity bill is one kilowatt-hour.

SymbolMeaningUnit
Power What the machine draws W
Hours Running time a day h
Rate Your tariff per unit ₹/kWh

Worked example

A 150 W machine, eight hours a day, 30 days a month, at ₹8 a unit:

Energy a day = 150 / 1000 x 8 = 1.2 kWh
Cost a month = 1.2 x 30 x 8    = 288

₹3,456 a year for the machine alone, before the monitor.

Notes and limits

  • The monitor is a separate load and is not in this figure unless you measured the whole desk together. The monitor electricity cost calculator takes it.
  • A desktop's draw is not constant. Idle, browsing and a game or a render are several times apart, so the honest version of this answer is a range.
  • Sleep draws a few watts rather than none, and a machine left on overnight for months adds up even at idle.
  • Indian tariffs are slabbed, so the marginal rate that a computer's consumption falls into may be higher than your average rate.

What this calculation assumes

  • The power figure is one you entered, and the result is most sensitive to it.
  • The machine is assumed to draw that power for the whole time it is on.
  • This is energy cost at the rate you entered. An Indian bill also carries fixed charges, slabs, duty and taxes.

Frequently asked questions

How much electricity does a PC use?

That depends entirely on the machine - an office desktop might draw 60 W and a gaming build 500 W under load. Measure yours with a plug-in energy meter rather than trusting a general figure, which is why this page asks rather than assuming.

Should I use the power supply rating?

No - it is a maximum, not a consumption figure. A machine with a 750 W supply may draw 90 W while you read email. Using the rating would overstate the bill several times over.

Is it cheaper to leave the PC on or shut it down?

Shutting down uses less electricity; sleep uses a few watts. Whether the difference is worth the wait depends on your tariff and how long the gaps are - this page will cost both if you run it twice.

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