Electric Charge Converter
Convert electric charge between coulombs, millicoulombs, microcoulombs, nanocoulombs, and ampere-hours. Enter a value, then select the From unit and To unit.
Convert Electric Charge Between Units
Electric Charge Formula
Where:
- \(Q_{\mathrm{from}}\) — the entered electric charge in the selected From unit
- \(Q_{\mathrm{to}}\) — the converted electric charge in the selected To unit
- \(f_{\mathrm{from}}\) and \(f_{\mathrm{to}}\) — the number of coulombs per unit for the selected From unit and To unit
The calculator converts the entered value to coulombs, then divides by the number of coulombs in one target unit. The conversion factors for every supported unit are listed below.
Electric Charge – Calculation Example
Example: convert the default value of 1 coulomb (C) to millicoulombs (mC). One coulomb is 1 C, and one millicoulomb is 0.001 C.
\[Q_{\mathrm{mC}}=1\times\frac{1}{0.001}=1000\,\mathrm{mC}\]
Result: 1 C = 1,000 mC.
How to use the calculator
- Enter a nonnegative number in Electric charge value.
- Choose its current unit in From unit.
- Choose the unit you want in To unit.
- Read the converted number and unit under Converted Electric Charge. To reverse the conversion, swap the two unit selections.
For example, to express a battery capacity of 2.5 Ah as charge in coulombs, enter 2.5, select Ampere-hour (Ah) as the From unit, and select Coulomb (C) as the To unit. The result is 9,000 C. Selecting the same unit in both menus leaves the entered value unchanged, apart from any rounding in the displayed result.
What electric charge measures
Electric charge is a property of matter that determines how it responds to electric and magnetic fields. The coulomb (C) is the SI unit of charge. A charge of 1 C passes a point when a current of 1 ampere flows for 1 second, so \(1\,\mathrm{C}=1\,\mathrm{A}\cdot\mathrm{s}\). Charge and current are related but not interchangeable: current describes how quickly charge flows. If you need to change current units rather than charge units, use the Electric Current converter.
Millicoulombs, microcoulombs, and nanocoulombs express smaller quantities of the same charge. Their prefixes mean one thousandth, one millionth, and one billionth of a coulomb, respectively. Choosing a suitably sized unit makes a result easier to read: 0.005 C is 5 mC or 5,000 µC. The numeric value changes with the unit, but the physical amount of charge does not.
An ampere-hour (Ah) is also a unit of charge, commonly used to state battery capacity. It is the charge corresponding to a current of 1 A sustained for 1 hour: \(1\,\mathrm{Ah}=3{,}600\,\mathrm{C}\). That equivalence converts charge, not battery energy. Energy also depends on voltage and operating conditions; an Ah rating alone does not tell you how many watt-hours a battery will deliver.
Supported units and conversion factors
Each factor below is the number of coulombs in one unit. Multiply a value by its factor to obtain coulombs; divide a value in coulombs by the target unit’s factor to complete the conversion.
| Unit | Symbol | Coulombs per unit |
|---|---|---|
| Coulomb | C | 1 |
| Millicoulomb | mC | 0.001 |
| Microcoulomb | µC | 0.000001 |
| Nanocoulomb | nC | 0.000000001 |
| Ampere-hour | Ah | 3,600 |
For a quick check, converting 1 µC to nC uses the factors 0.000001 and 0.000000001. Dividing the first by the second gives 1,000 nC. The same method works in either direction and for every pair of units in the menus.
Practical limits
The input accepts zero and positive values, but not negative values. Charge can be positive or negative in physics; this converter handles only the nonnegative magnitude you enter. It does not determine a charge’s sign, the direction of current, or whether charge is stored, transferred, or distributed across an object.
The displayed result is rounded to six decimal places. Very small results may therefore appear as zero even though the underlying conversion is not zero. If that happens, choose a smaller To unit—such as nC instead of C—or convert in the opposite direction to inspect the scale. The menu supports only C, mC, µC, nC, and Ah; units such as milliampere-hours and elementary charges are not available here.
Converting charge does not describe how a circuit behaves. Resistance and conductance, for instance, are separate electrical quantities. Use the converted charge alongside the appropriate time, current, or circuit measurements when interpreting a practical result.
Frequently Asked Questions
How do I calculate electric charge from current and time?
Multiply current in amperes by time in seconds: \(Q=It\). For example, a steady current of 0.25 A flowing for 8 seconds transfers \(0.25\times8=2\) C of charge. If the current changes over time, multiplying by one current value is only an approximation; use the average current over the interval or integrate the current.
How do I convert milliampere-hours (mAh) to coulombs?
Multiply the mAh value by 3.6 to get coulombs. A milliampere-hour is one-thousandth of an ampere-hour, so \(1\,\mathrm{mAh}=3.6\,\mathrm{C}\). For example, 750 mAh is 2,700 C. Because mAh is not a menu option, divide by 1,000 first to enter the value in Ah.
What is a normal or good amount of electric charge?
There is no universally normal or good charge value; it depends on what you are measuring. A tiny electronic component may involve nanocoulombs or microcoulombs, while a battery capacity is often stated in ampere-hours. A larger charge is not automatically better. Compare values only when the device, measurement conditions, and intended use are comparable.
How do I find the charge stored on a capacitor?
Multiply its capacitance by the voltage across it: \(Q=CV\), where capacitance is in farads and voltage is in volts. A 10 µF capacitor at 5 V holds \(50\,\mathrm{\mu C}\) on each plate in magnitude; the plates have opposite signs. Use the voltage actually measured across the capacitor, not necessarily the supply voltage.
How many electrons correspond to one nanocoulomb?
One nanocoulomb corresponds to about 6.24 billion elementary charges. Divide the charge in coulombs by the magnitude of one electron’s charge, approximately \(1.602\times10^{-19}\,\mathrm{C}\). This gives a count of elementary charges, not necessarily the number of electrons moving through a particular device; a net positive charge can instead mean an electron deficit.
Can I convert ampere-hours directly to watt-hours?
You also need a voltage to estimate energy: \(\mathrm{Wh}\approx\mathrm{Ah}\times\mathrm{V}\). For example, 4 Ah at a nominal 12 V is approximately 48 Wh. This is an estimate because battery voltage changes during discharge, and usable capacity depends on conditions such as load and temperature. An electric-charge conversion alone cannot establish delivered energy.