Coulombs (C)
The coulomb is the SI unit of electric charge, the charge transported by a current of one ampere in one second.
Convert coulombs to any charge unit
1 coulomb = 0.2777777778 milliampere-hours
Quick facts
- Unit
- Coulomb (plural: coulombs)
- Symbol
- C
- Measures
- Electric Charge
- System
- Common
- Definition
- The charge carried by 1 ampere in 1 second (1 A·s).
1 coulomb in other units
| Milliampere-hours | 0.2777777778 mAh |
| Ampere-hours | 0.000277777778 Ah |
| Elementary charges | 6.2415091 × 1018 e |
| Faradays | 0.00001036427 F |
What is a coulomb?
The coulomb is the SI unit of electric charge, the charge transported by a current of one ampere in one second. It is named after Charles-Augustin de Coulomb, who measured the force between charges in the 1780s. One coulomb is about 6.24 × 10¹⁸ electrons.
Where the coulomb sits among charge units
The coulomb is number 8 of 17 on our scale of charge units, ordered from smallest to largest.
Coulombs in real life
- A lightning bolt carries about 15 C
- A fully charged smartphone battery holds about 15,000 C
- Rubbing a balloon on hair transfers about 0.1 µC
Top coulomb conversions
Common amounts of coulombs
- 0.1 C
- 0.2 C
- 0.3 C
- 0.4 C
- 0.5 C
- 0.6 C
- 0.7 C
- 0.8 C
- 0.9 C
- 1 C
- 1.5 C
- 2 C
- 2.5 C
- 3 C
- 3.5 C
- 4 C
- 4.5 C
- 5 C
- 6 C
- 7 C
- 7.5 C
- 8 C
- 9 C
- 10 C
- 11 C
- 12 C
- 13 C
- 14 C
- 15 C
- 16 C
- 17 C
- 18 C
- 19 C
- 20 C
- 21 C
- 22 C
- 23 C
- 24 C
- 25 C
- 26 C
- 27 C
- 28 C
- 29 C
- 30 C
- 31 C
- 32 C
- 33 C
- 34 C
- 35 C
- 36 C
- 37 C
- 38 C
- 39 C
- 40 C
- 41 C
- 42 C
- 43 C
- 44 C
- 45 C
- 46 C
- 47 C
- 48 C
- 49 C
- 50 C
- 51 C
- 52 C
- 53 C
- 54 C
- 55 C
- 56 C
- 57 C
- 58 C
- 59 C
- 60 C
- 61 C
- 62 C
- 63 C
- 64 C
- 65 C
- 66 C
- 67 C
- 68 C
- 69 C
- 70 C
- 71 C
- 72 C
- 73 C
- 74 C
- 75 C
- 76 C
- 77 C
- 78 C
- 79 C
- 80 C
- 81 C
- 82 C
- 83 C
- 84 C
- 85 C
- 86 C
- 87 C
- 88 C
- 89 C
- 90 C
- 91 C
- 92 C
- 93 C
- 94 C
- 95 C
- 96 C
- 97 C
- 98 C
- 99 C
- 100 C
- 110 C
- 120 C
- 130 C
- 140 C
- 150 C
- 160 C
- 170 C
- 180 C
- 190 C
- 200 C
- 210 C
- 220 C
- 230 C
- 240 C
- 250 C
- 260 C
- 270 C
- 280 C
- 290 C
- 300 C
- 310 C
- 320 C
- 330 C
- 340 C
- 350 C
- 360 C
- 370 C
- 380 C
- 390 C
- 400 C
- 410 C
- 420 C
- 430 C
- 440 C
- 450 C
- 460 C
- 470 C
- 480 C
- 490 C
- 500 C
- 600 C
- 700 C
- 800 C
- 900 C
- 1,000 C
- 1,200 C
- 1,500 C
- 2,000 C
- 2,500 C
- 3,000 C
- 4,000 C
- 5,000 C
- 10,000 C
Convert coulombs to all 16 other units
Common
Metric prefixes
CGS & natural
Convert to coulombs
Frequently asked questions
What is a coulomb?
The coulomb is the SI unit of electric charge, the charge transported by a current of one ampere in one second.
How is the coulomb defined?
The charge carried by 1 ampere in 1 second (1 A·s).
How many milliampere-hours are in a coulomb?
One coulomb equals 0.2777777778 milliampere-hours.
How many ampere-hours are in a coulomb?
One coulomb equals 0.000277777778 ampere-hours.
How many elementary charges are in a coulomb?
One coulomb equals 6.2415091e18 elementary charges.