Mobile & Electronics

Phone Charging Cost Calculator

What charging your phone actually costs a month - a figure that surprises people in the reassuring direction.

8 inputs Free, no sign-up

Your figures

From your phone's specifications. Most phones sold in India are between 4,500 and 6,000 mAh, but use your own figure.

Usually 3.7 V or 3.85 V nominal, printed on the battery or in the specifications. Not assumed for you, since the two differ by 4%.

Leave blank for this page's 85% assumption.

One full charge a day is typical. Use 1.5 or 2 for heavy use.

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

Charging a phone costs a few rupees a month, and the exact figure is worth knowing because people routinely overestimate it. A 5,000 mAh phone charged once a day for a whole year costs under seventy rupees at a typical Indian tariff.

That is the useful result: whatever is driving your electricity bill, it is not the phone. The geyser, the air conditioner and the fridge are where the money goes.

How to use this calculator

  1. Enter your phone's battery capacity from its specifications.
  2. Enter the battery voltage — usually 3.7 V or 3.85 V, and worth checking since they differ by 4%.
  3. Set how often you charge and your rate per unit.

The formula

Battery energy = Capacity (Ah) x Voltage
From socket    = Battery energy / Efficiency
Cost a charge  = From socket in kWh x Rate
Cost a month   = Cost a charge x charges a month

The energy pulled from the socket is larger than the energy stored, because charging loses some as heat. At 85% efficiency, an 19.25 Wh phone battery draws about 22.6 Wh from the wall.

SymbolMeaningUnit
Capacity Phone battery capacity mAh
V Battery voltage V
Efficiency Share reaching the cell %
Rate Your tariff per unit Rs/kWh

Worked example

A 5,000 mAh phone at 3.85 V, charged once a day, at ₹8.50 a unit:

Battery energy = 5 x 3.85       = 19.25 Wh
From socket    = 19.25 / 0.85    = 22.65 Wh
Per charge     = 0.02265 x 8.50  = Rs 0.19
Per month                        = Rs 5.78
Per year                         = Rs 69.30

Under six rupees a month. A single hour of a 1.5 kW geyser costs more than two months of phone charging.

Notes and limits

  • The figure is small, and that is the answer rather than a rounding problem. Phone charging is not a meaningful part of a household bill.
  • No phone's specifications ship with this calculator. Your capacity and voltage come from your own phone, because guessing them would be inventing a specification.
  • Most days are not a full charge from empty. Topping up from 40% costs proportionally less, so the monthly figure is an upper bound for typical use.
  • A charger left plugged in with no phone attached draws a fraction of a watt continuously. Over a year that is comparable to the charging itself.
  • Fast charging is marginally less efficient, so it costs a little more per charge.

What this calculation assumes

  • Each charge is a full one from empty, which makes the monthly figure an upper bound.
  • Efficiency is your figure or this page's 85% assumption.
  • Idle charger consumption is not included.
  • No phone specifications are supplied; the capacity and voltage are yours.

Frequently asked questions

How much does it cost to charge a phone in India?

About 19 paise for a full charge of a 5,000 mAh phone at Rs 8.50 a unit - roughly Rs 6 a month or Rs 70 a year if you charge once a day.

Does fast charging cost more?

Marginally. Higher currents mean proportionally more energy lost as heat, so a fast charge is slightly less efficient. The difference is a few paise.

Should I unplug my charger when not charging?

It saves a small amount - an idle charger draws a fraction of a watt, which over a year is comparable to what the charging itself costs. Worth doing, not worth worrying about.

What voltage should I enter?

Whatever your battery says - usually 3.7 V or 3.85 V nominal. This page does not fill it in for you because the two differ by about 4%, and the figure is in your phone's specifications.

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