Unit systemSI derived unit
Unit ofElectric charge
Named afterCharles-Augustin de Coulomb
1 C in ...... is equal to ...
   SI base units   As
   CGS units   2997924580 statC
   Atomic units   6.24150934(14)e×10^18[1]

The coulomb (symbol: C) is the International System of Units (SI) unit of electric charge. It is the charge (symbol: Q or q) transported by a constant current of one ampere in one second:

Thus, it is also the amount of excess charge on a capacitor of one farad charged to a potential difference of one volt:

The coulomb is equivalent to the charge of approximately 6.242×1018 (1.036×10−5 mol) protons, and −1 C is equivalent to the charge of approximately 6.242×1018 electrons.

A new definition, in terms of the elementary charge, will take effect on 20 May 2019.[2] The new definition, defines the elementary charge (the charge of the proton) as exactly 1.602176634×10−19 coulombs. This would implicitly define the coulomb as ​10.1602176634×1018 elementary charges.

Name and notation

This SI unit is named after Charles-Augustin de Coulomb. As with every International System of Units (SI) unit named for a person, the first letter of its symbol is upper case (C). However, when an SI unit is spelled out in English, it is treated as a common noun and should always begin with a lower case letter (coulomb)—except in a situation where any word in that position would be capitalized, such as at the beginning of a sentence or in material using title case.[3]

Other Languages
Afrikaans: Coulomb
العربية: كولوم
অসমীয়া: কুলম্ব
asturianu: Culombiu
azərbaycanca: Kulon (ölçü vahidi)
تۆرکجه: کولون
বাংলা: কুলম্ব
беларуская (тарашкевіца)‎: Кулён
български: Кулон
བོད་ཡིག: ཁུ་ལོམ།
bosanski: Kulon
brezhoneg: Coulomb
català: Coulomb
čeština: Coulomb
Cymraeg: Coulomb
dansk: Coulomb
Deutsch: Coulomb
dolnoserbski: Coulomb
eesti: Kulon
español: Culombio
euskara: Coulomb
فارسی: کولن
français: Coulomb
Gaeilge: Cúlóm
galego: Coulomb
한국어: 쿨롬
हिन्दी: कूलम्ब
hornjoserbsce: Coulomb
hrvatski: Kulon
Bahasa Indonesia: Coulomb
íslenska: Kúlomb
italiano: Coulomb
עברית: קולון
ქართული: კულონი
қазақша: Кулон
Kreyòl ayisyen: Koulon
kurdî: Coulomb
latviešu: Kulons
lietuvių: Kulonas
Ligure: Coulomb
magyar: Coulomb
македонски: Кулон
മലയാളം: കൂളംബ്
मराठी: कूलोंब
Bahasa Melayu: Coulomb
монгол: Кулон
မြန်မာဘာသာ: ကူးလောင်း
Nederlands: Coulomb (eenheid)
日本語: クーロン
Nordfriisk: Coulomb
norsk: Coulomb
norsk nynorsk: Coulomb
occitan: Coulomb
oʻzbekcha/ўзбекча: Kulon
پنجابی: کولمب
Piemontèis: Coulomb
polski: Kulomb
português: Coulomb
русский: Кулон
Scots: Coulomb
sicilianu: Coulomb
Simple English: Coulomb
slovenčina: Coulomb
slovenščina: Coulomb
српски / srpski: Кулон
srpskohrvatski / српскохрватски: Kulon (jedinica)
suomi: Coulombi
svenska: Coulomb
தமிழ்: கூலும்
татарча/tatarça: Кулон
Türkçe: Coulomb
українська: Кулон (одиниця)
اردو: کولمب
Tiếng Việt: Coulomb (đơn vị)
ייִדיש: קולאמב
粵語: 庫倫
中文: 库仑