Amperes (A)
The ampere is the SI base unit of electric current.
Convert amperes to any current unit
1 ampere = 1,000 milliamperes
Quick facts
- Unit
- Ampere (plural: amperes)
- Symbol
- A
- Measures
- Electric Current
- System
- Common
- Definition
- The current of exactly 1/1.602176634 × 10¹⁹ elementary charges per second.
- Also written
- amp, amps
1 ampere in other units
| Milliamperes | 1,000 mA |
| Microamperes | 1,000,000 µA |
| Kiloamperes | 0.001 kA |
What is an ampere?
The ampere is the SI base unit of electric current. One ampere is one coulomb of charge per second. Since 2019 it has been defined by fixing the elementary charge. Fuses, circuit breakers, chargers and cables are all rated in amps.
Where the ampere sits among current units
The ampere is number 7 of 11 on our scale of current units, ordered from smallest to largest.
What amperes are used for
- Circuit breakers and fuses
- Chargers and power supplies
- Cable and wire ratings
Amperes in real life
- A USB-C phone charger delivers about 2–3 A
- A kettle draws about 10 A at 230 V
- US household circuits are usually 15 or 20 A
Top ampere conversions
Common amounts of amperes
- 0.1 A
- 0.2 A
- 0.3 A
- 0.4 A
- 0.5 A
- 0.6 A
- 0.7 A
- 0.8 A
- 0.9 A
- 1 A
- 1.5 A
- 2 A
- 2.5 A
- 3 A
- 3.5 A
- 4 A
- 4.5 A
- 5 A
- 6 A
- 7 A
- 7.5 A
- 8 A
- 9 A
- 10 A
- 11 A
- 12 A
- 13 A
- 14 A
- 15 A
- 16 A
- 17 A
- 18 A
- 19 A
- 20 A
- 21 A
- 22 A
- 23 A
- 24 A
- 25 A
- 26 A
- 27 A
- 28 A
- 29 A
- 30 A
- 31 A
- 32 A
- 33 A
- 34 A
- 35 A
- 36 A
- 37 A
- 38 A
- 39 A
- 40 A
- 41 A
- 42 A
- 43 A
- 44 A
- 45 A
- 46 A
- 47 A
- 48 A
- 49 A
- 50 A
- 51 A
- 52 A
- 53 A
- 54 A
- 55 A
- 56 A
- 57 A
- 58 A
- 59 A
- 60 A
- 61 A
- 62 A
- 63 A
- 64 A
- 65 A
- 66 A
- 67 A
- 68 A
- 69 A
- 70 A
- 71 A
- 72 A
- 73 A
- 74 A
- 75 A
- 76 A
- 77 A
- 78 A
- 79 A
- 80 A
- 81 A
- 82 A
- 83 A
- 84 A
- 85 A
- 86 A
- 87 A
- 88 A
- 89 A
- 90 A
- 91 A
- 92 A
- 93 A
- 94 A
- 95 A
- 96 A
- 97 A
- 98 A
- 99 A
- 100 A
- 110 A
- 120 A
- 130 A
- 140 A
- 150 A
- 160 A
- 170 A
- 180 A
- 190 A
- 200 A
- 210 A
- 220 A
- 230 A
- 240 A
- 250 A
- 260 A
- 270 A
- 280 A
- 290 A
- 300 A
- 310 A
- 320 A
- 330 A
- 340 A
- 350 A
- 360 A
- 370 A
- 380 A
- 390 A
- 400 A
- 410 A
- 420 A
- 430 A
- 440 A
- 450 A
- 460 A
- 470 A
- 480 A
- 490 A
- 500 A
- 600 A
- 700 A
- 800 A
- 900 A
- 1,000 A
- 1,200 A
- 1,500 A
- 2,000 A
- 2,500 A
- 3,000 A
- 4,000 A
- 5,000 A
- 10,000 A
Convert amperes to all 10 other units
Common
CGS
Convert to amperes
Frequently asked questions
What is an ampere?
The ampere is the SI base unit of electric current.
How is the ampere defined?
The current of exactly 1/1.602176634 × 10¹⁹ elementary charges per second.
How many milliamperes are in an ampere?
One ampere equals 1,000 milliamperes.
How many microamperes are in an ampere?
One ampere equals 1,000,000 microamperes.
How many kiloamperes are in an ampere?
One ampere equals 0.001 kiloamperes.