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Electric Charge Converter

Science

Convert electric charge units: coulombs, milliampere-hours, and ampere-hours. Essential for battery design, electronics hobbyists, and electrical engineers.

Reviewed by the thecalcu.com team · Last updated June 23, 2026

From
To
All conversionsfor 1 Milliampere-hour (mAh)
Coulomb (C)3.6
Millicoulomb (mC)3600
Microcoulomb (μC)3600000
Nanocoulomb (nC)3600000000
Picocoulomb (pC)3.6000e+12
Kilocoulomb (kC)0.0036
Microampere-hour (μAh)1000
Milliampere-hour (mAh)1
Ampere-hour (Ah)0.001
Faraday (F)0.000037311371
Elementary Charge (e)2.2469e+19

What is a Charge?

An Electric Charge Converter converts between units that measure the quantity of electric charge, a fundamental property of matter that determines how it interacts with electromagnetic fields. Charge is the "how much electricity" quantity, as distinct from current (how fast charge flows) or voltage (the force driving charge flow).

The SI unit is the coulomb (C), defined as the charge transported by one ampere of current in one second. However, coulombs are rarely used in everyday electronics, battery specifications, power banks, mobile phones, and EV chargers in India express capacity in milliampere-hours (mAh) or ampere-hours (Ah).

This converter handles 11 units across three groups:

  • SI prefix variants, coulomb, millicoulomb, microcoulomb, nanocoulomb, picocoulomb, kilocoulomb
  • Practical battery units, microampere-hour (μAh), milliampere-hour (mAh), ampere-hour (Ah)
  • Physics units, Faraday (electrochemistry), Elementary charge (quantum electronics)

For Indian users, the most relevant conversions are mAh ↔ coulombs (for battery chemistry calculations) and Ah ↔ kC (for industrial battery systems). The Indian EV industry, which includes Tata Motors, Ola Electric, and Ather Energy, specifies battery capacity in kWh at the pack level, but cell-level charge is expressed in Ah, and converting between these is essential for battery management system (BMS) design.

Use the Energy Converter alongside this when also converting watt-hours (Wh = charge in Ah × voltage in V).

Why Use an Electric Charge Converter?

The conversion from mAh to coulombs, multiplying by 3.6, is simple but rarely memorised correctly, especially when working under deadline with coulombs and mAh appearing in the same calculation. The Faraday constant (96,485 C) and elementary charge (1.602 × 10⁻¹⁹ C) are easy to misremember without reference.

Two concrete Indian use cases:

  1. Battery management system (BMS) design: An engineer at an EV startup in Pune is sizing the BMS state-of-charge algorithm. The cell datasheet rates capacity at 3.0 Ah. Converting to coulombs for the integration formula: 3.0 × 3600 = 10,800 C. The BMS integrates current over time in ampere-seconds (= coulombs) to track remaining charge.

  2. Electroplating process control: A galvanising factory in Moradabad needs to deposit 50g of silver (atomic mass 107.87 g/mol, monovalent) on jewellery components. Charge required = (50/107.87) × 96485 = 44,694 C = 12.41 Ah. Knowing the plating bath current, they can calculate the required plating time.

Who Should Use This Converter?

Electronics engineers and hobbyists comparing battery specifications, calculating whether a 3000 mAh battery provides enough charge for a circuit running at a given current draw.

Battery and EV engineers converting between Ah (cell-level specification) and coulombs (BMS algorithms) when designing or testing battery management systems for India's growing EV industry.

Electrochemistry students and researchers working with Faraday's laws of electrolysis, where deposited mass calculations require charge in coulombs or Faradays.

Semiconductor and VLSI engineers working with charge in picocoulombs and nanocoulombs for capacitor discharge calculations, ESD (electrostatic discharge) protection design, and signal integrity analysis.

Physics students studying electromagnetic theory, where charge appears in Coulomb's law, Gauss's law, and capacitor calculations. For power calculations, also see the Power Converter.

What Insights Does the Electric Charge Converter Give You?

The converted value gives you the direct equivalent, e.g. "how many coulombs is 5000 mAh?" (18,000 C).

The reference table shows the same charge value in all 11 units simultaneously. This is particularly useful when writing battery specifications that must satisfy multiple standards: cell datasheets (mAh), BMS firmware (coulombs), and electrochemistry protocols (Faradays).

Practical charge reference guide:

Item Charge (mAh) Charge (C)
Hearing aid battery 100–300 mAh 360–1,080 C
Typical smartphone 3,500–5,000 mAh 12,600–18,000 C
Laptop battery 4,000–8,000 mAh 14,400–28,800 C
EV cell (18650) 2,500–3,500 mAh 9,000–12,600 C
1 Faraday 26,802 mAh 96,485 C

How to use this Charge calculator

  1. The converter loads with Milliampere-hour (mAh) as the FROM unit and Coulomb (C) as the TO unit, the most common battery engineering conversion.
  2. Select your source unit from the FROM dropdown. Units are grouped: SI, Practical (mAh/Ah), and Physics (Faraday, elementary charge).
  3. Enter the charge value in the input field. The result updates immediately.
  4. Select your target unit from the TO dropdown.
  5. Use the ⇅ swap button to reverse the conversion, useful when you have coulombs from a calculation and need the mAh equivalent.
  6. Scroll to the reference table to see the value in all 11 units simultaneously.
  7. For battery energy calculations, multiply the Ah result by battery voltage (in volts) to get watt-hours, then use the Energy Converter to convert Wh to kWh or joules.

Formula & Methodology

This is a linear converter using the coulomb (C) as the common base unit. All conversions follow:

Result = Input × (toBase_from ÷ toBase_to)

Key toBase values (coulombs):

| Unit | Coulombs |
|---|---|
| Coulomb (C) | 1 |
| Millicoulomb (mC) | 0.001 |
| Microcoulomb (μC) | 1 × 10⁻⁶ |
| Nanocoulomb (nC) | 1 × 10⁻⁹ |
| Picocoulomb (pC) | 1 × 10⁻¹² |
| Kilocoulomb (kC) | 1,000 |
| Microampere-hour (μAh) | 0.0036 |
| Milliampere-hour (mAh) | 3.6 |
| Ampere-hour (Ah) | 3,600 |
| Faraday (F) | 96,485.332 |
| Elementary Charge (e) | 1.60218 × 10⁻¹⁹ |

Derivations:
- 1 mAh = 0.001 A × 3600 s = 3.6 C (exact, from SI definitions)
- 1 Ah = 1 A × 3600 s = 3600 C (exact)
- 1 Faraday = Avogadro's number × elementary charge = 6.02214076 × 10²³ × 1.602176634 × 10⁻¹⁹ = 96,485.332 C
- 1 elementary charge = 1.602176634 × 10⁻¹⁹ C (exact per 2019 SI redefinition)

Worked example, Pune EV startup:
A lithium cell is rated at 2800 mAh. Convert to coulombs and Ah for BMS calculations:

Coulombs: 2800 × 3.6 = 10,080 C Ah:       2800 × 3.6 ÷ 3600 = 2.8 Ah kC:       10,080 ÷ 1000 = 10.08 kC

In Faradays: 10,080 ÷ 96,485 ≈ 0.1045 F, this means the cell can deliver about 10.45% of one mole of electrons from full charge to empty.

Related Tools

You may also find these useful: Electric Resistance Converter.

Frequently Asked Questions

Electric charge is a fundamental physical property of matter that causes it to experience a force in an electromagnetic field. The SI unit of charge is the coulomb (C), defined as the charge transported by a current of one ampere in one second. Charge can be positive (protons) or negative (electrons), and like charges repel while opposite charges attract. In practical electronics, charge is most commonly expressed as milliampere-hours (mAh) for battery capacity rather than coulombs.
Coulombs and milliampere-hours both measure electric charge but are used in different contexts. One milliampere-hour (mAh) equals 3.6 coulombs, the charge delivered by 1 mA current flowing for one hour (1 mA × 3600 s = 3.6 C). Coulombs are the SI standard used in physics calculations, while mAh is the practical unit used for battery capacity ratings on phones, laptops, power banks, and other consumer electronics.
mAh (milliampere-hours) on a battery indicates how much charge the battery can store and deliver. A 5000 mAh battery can supply 5000 mA (5A) for one hour, or 500 mA for ten hours, or 100 mA for 50 hours. A typical Indian smartphone has a battery of 4000–5000 mAh; a laptop battery is typically 4000–8000 mAh (but expressed as Wh = mAh × voltage at the pack). In coulombs, 5000 mAh = 5000 × 3.6 = 18,000 C.
To convert milliampere-hours to coulombs, multiply by 3.6. For example, 3000 mAh × 3.6 = 10,800 C. To convert coulombs back to mAh, divide by 3.6. This conversion comes from the relationship: 1 mAh = 0.001 A × 3600 s = 3.6 A·s = 3.6 C. For Ah to coulombs, multiply by 3600.
A Faraday (named after Michael Faraday) is the amount of electric charge carried by one mole of electrons, approximately 96,485 coulombs. It is fundamental to electrochemistry: in electrolysis and electroplating, one Faraday of charge deposits one mole of a monovalent element (such as silver). For a divalent element like copper, two Faradays deposit one mole. Indian electroplating and galvanising industries use Faraday calculations when optimising current-time-mass relationships in plating baths.
The elementary charge (e) is the electric charge carried by a single proton or the magnitude of charge on a single electron: exactly 1.602176634 × 10⁻¹⁹ coulombs (exact since the 2019 SI redefinition). It is the smallest discrete unit of electric charge that exists in isolation. In semiconductor physics and quantum electronics, charge is often quantified as multiples of e. 1 coulomb contains approximately 6.242 × 10¹⁸ elementary charges.
Indian consumer electronics specifications use mAh for battery capacity, mobile phones, power banks, EV batteries (also expressed as Wh or kWh). Industrial battery systems and EV charging infrastructure in India use Ah and kAh for large-capacity storage. Semiconductor and nanotechnology research labs use picocoulombs (pC) and nanocoulombs (nC). Electrochemistry and electroplating, significant industries in Rajkot, Moradabad, and other Indian manufacturing hubs, use Faradays and coulombs for process calculations.
Select your source unit from the FROM dropdown, for example, Milliampere-hour (mAh). Enter the charge value in the input field. Select your target unit from the TO dropdown, for example, Coulomb (C). The converted result appears immediately. Use the ⇅ swap button to reverse the conversion, and scroll to the reference table to see the charge expressed in all 11 units at once.
A smartphone battery rated at 4500 mAh contains 4500 × 3.6 = 16,200 coulombs of charge. In Ah, this is 4.5 Ah. In kilocoulombs, it is 16.2 kC. In terms of elementary charges, this represents 16,200 ÷ 1.602 × 10⁻¹⁹ ≈ 1.01 × 10²³ electrons, about one sixth of Avogadro's number. A large EV battery pack (e.g. 75 kWh at 400V) holds approximately 675 Ah = 2,430,000 C.
Electric charge (Q, measured in coulombs) is the quantity of electricity, how much. Electric current (I, measured in amperes) is the rate of flow of charge, how fast. The relationship is I = Q/t, or equivalently Q = I × t. A 1 ampere current flowing for 1 second delivers 1 coulomb of charge. This is why battery capacity in Ah (ampere-hours) converts to coulombs by multiplying by 3600 seconds per hour.
The charge stored on a capacitor is Q = C × V, where Q is charge in coulombs, C is capacitance in farads, and V is voltage in volts. A 100 μF capacitor charged to 12V stores 100 × 10⁻⁶ × 12 = 0.0012 C = 1200 μC. This relationship is central to electronics circuit design, understanding charge helps size capacitors for power supply filtering, flash circuits, and energy storage applications. The Capacitance Converter handles farad unit conversions.
All charge units in this converter are linear, using the coulomb as the base: Result = Input × (toBase_from ÷ toBase_to). Key relationships: 1 mAh = 3.6 C; 1 Ah = 3600 C; 1 Faraday = 96,485.332 C; 1 elementary charge = 1.60218 × 10⁻¹⁹ C. For example, to convert 2000 mAh to Ah: 2000 × 3.6 ÷ 3600 = 2 Ah.
Also known as
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