Convert ESU of Charge to Elementary Charges
ESU of Charge (ESU) to Elementary Charge (e) charge conversion — enter any value below to get an instant result, or use the table for common values.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 ESU = 2.08194E+09 e
1 ESU of Charge = 2.08194E+09 Elementary Charges
1 Elementary Charge = 4.80321E-10 ESU of Charge
1 ESU in every supported unit
Conversion chart: ESU of Charge to Elementary Charges
Conversion table
| ESU of Charge (ESU) | Elementary Charge (e) |
|---|---|
| 0.01 ESU | 20819424 e |
| 0.1 ESU | 2.0819424E+08 e |
| 1 ESU | 2.08194E+09 e |
| 2 ESU | 4.16388E+09 e |
| 3 ESU | 6.24583E+09 e |
| 5 ESU | 1.04097E+10 e |
| 10 ESU | 2.08194E+10 e |
| 20 ESU | 4.16388E+10 e |
| 50 ESU | 1.04097E+11 e |
| 100 ESU | 2.08194E+11 e |
| 1000 ESU | 2.08194E+12 e |
ESU of Charge (ESU)
Definition: The generic "electrostatic unit" name for the CGS-ESU charge unit — numerically identical to, and interchangeable with, the statcoulomb.
History: It shares its origin with the statcoulomb, both arising from the electrostatic branch of the 19th-century CGS unit system.
Current use: Appears in older chemistry and physics texts describing dipole moments and ionic charges generically "in ESU" rather than naming statcoulomb specifically.
Elementary Charge (e)
Definition: The magnitude of the electric charge carried by a single proton (or, with opposite sign, a single electron) — the smallest unit of free electric charge and the fundamental quantum that all other charge quantities are built from.
History: First measured with precision by Robert Millikan's oil-drop experiments between 1909 and 1913; since the 2019 redefinition of the SI, its value is fixed by definition and used to define the coulomb itself, rather than being measured relative to it.
Current use: A fundamental constant used throughout particle physics, semiconductor device physics, and quantum charge-transport calculations wherever charge must be counted in discrete elementary units rather than treated as a continuous quantity.
Supported Units
| Unit | Symbol | In Coulomb |
|---|---|---|
| Megacoulomb | MC | 1000000 C |
| Kilocoulomb | kC | 1000 C |
| Coulomb | C | 1 C |
| Millicoulomb | mC | 0.001 C |
| Microcoulomb | µC | 1E-06 C |
| Nanocoulomb | nC | 1E-09 C |
| Picocoulomb | pC | 1E-12 C |
| Abcoulomb | abC | 10 C |
| EMU of Charge | EMU | 10 C |
| Statcoulomb | statC | 3.33564E-10 C |
| ESU of Charge | ESU | 3.33564E-10 C |
| Franklin | Fr | 3.33564E-10 C |
| Ampere-Hour | A·h | 3600 C |
| Ampere-Minute | A·min | 60 C |
| Ampere-Second | A·s | 1 C |
| Faraday | F | 96485.309 C |
| Elementary Charge | e | 1.60218E-19 C |
About These Parameters
- Value
- The amount of electric charge you want to convert, expressed in the "From" unit. Accepts decimals, and can represent anything from a single elementary charge to a battery's full ampere-hour rating.
- From Unit
- The unit your input value is currently measured in — a battery datasheet's ampere-hour rating, an electrochemistry problem's faradays, or an older physics text's abcoulomb or statcoulomb figure.
- To Unit
- The unit you want the result converted into. Use the swap button to flip From and To instantly, which is handy when translating a historical CGS-system figure into the modern SI coulomb or vice versa.
How Charge Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the coulomb. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For ESU of Charge → Elementary Charge: multiply by 2.08194E+09. For example, 1 ESU × 2.08194E+09 = 2.08194E+09 e.
From CGS Charge Units to the SI Coulomb
Before the SI system unified electricity around the ampere and coulomb, 19th-century physicists working in the centimeter-gram-second (CGS) system built two competing "natural" families of electrical units: the electrostatic (ESU) family, whose charge unit is the statcoulomb (also called the franklin, honoring Benjamin Franklin), defined so that two one-statcoulomb charges one centimeter apart repel with exactly one dyne of force; and the electromagnetic (EMU) family, whose charge unit is the abcoulomb, equal to a much larger 10 coulombs. Both systems made Maxwell's equations take a cleaner mathematical form than SI does, which is why some theoretical-physics and plasma-physics literature still uses Gaussian (CGS) units today — this converter lets you move any of those historical figures straight into the modern coulomb.
Why Batteries, Chemistry, and Physics Each Use a Different Unit
Battery engineers rate capacity in ampere-hours because that's literally how a battery is specified and discharged — a steady current for a certain duration. Electrochemists use the faraday because Faraday's laws of electrolysis relate charge passed directly to moles of substance deposited or liberated at an electrode, so working in "moles of charge" (faradays) keeps the chemistry intuitive. Particle physicists use the elementary charge because it's the smallest indivisible unit of free charge in nature, making it the natural yardstick for counting electrons, protons, or ionization events one at a time. All three units describe exactly the same physical quantity — they just scale it to whatever a given field actually measures day to day.
Example
A charge of 1 ESU equals 2.08194E+09 e. For scale, a typical smartphone battery stores roughly 3,000-5,000 milliampere-hours (around 10,000-18,000 coulombs), a car battery is rated around 50-100 ampere-hours (180,000-360,000 coulombs), and a single lightning strike transfers on the order of 15-30 coulombs to the ground in well under a second.
Frequently Asked Questions
How many Elementary Charges are in 1 ESU of Charge?
1 ESU of Charge (ESU) equals exactly 2.08194E+09 Elementary Charges (e).
What's the difference between a coulomb and an ampere-hour?
Both measure electric charge, but on very different scales. A coulomb is the charge moved by one ampere in one second; an ampere-hour is the charge moved by one ampere over a full hour, which is 3,600 times larger. Batteries are rated in ampere-hours (or milliampere-hours) because that matches how they're actually discharged, while raw coulombs are more common in circuit-level physics calculations.
Why are abcoulomb and EMU of charge the same value?
"EMU of charge" is simply the generic name for the CGS electromagnetic system's charge unit, and "abcoulomb" is that same unit's specific name — they're not two different quantities, just two names for one unit, both equal to 10 coulombs. The same relationship holds for statcoulomb, ESU of charge, and franklin, which are three names for the same CGS electrostatic charge unit.
How is the faraday related to the elementary charge?
The faraday is the charge of one full mole of elementary charges — multiply Avogadro's number (about 6.022×10²³) by the elementary charge (about 1.602×10⁻¹⁹ coulomb) and you get the Faraday constant, roughly 96,485 coulombs per mole. It's the bridge electrochemists use between "how many electrons were transferred" and "how much charge passed through the circuit."
Is the elementary charge the smallest possible amount of charge?
For any freely existing particle, yes — every electron and proton carries exactly one elementary charge (with opposite sign), and no isolated particle has ever been observed with a smaller fraction of it. Quarks carry fractional charges of ±1/3 or ±2/3 of the elementary charge, but they're never observed in isolation, only bound inside composite particles whose overall charge is always a whole multiple of the elementary charge.