This article will show how to convert electric current measurement units from amperes (A) to milliamperes (mA). We will cover essential definitions, provide examples, share relevant formulas, and present tables, along with answers to common questions.
Definitions of Ampere and Milliampere
Let’s get started by understanding the key definitions of Ampere (A) and Milliampere (mA). Understanding these terms will allow you to perform conversions confidently.
What is an Ampere?
The ampere (A) is the SI base unit of electric current, representing the amount of charge flowing through a conductor per second.[1] It is defined based on the elementary charge (e), where 1 A = 1 coulomb per second (C/s).
"Amp" is an informal abbreviation commonly used in everyday conversation and electrical contexts, though "A" remains the official SI unit symbol.
According to SI prefixes[2], which are based on powers of 10, an ampere (1 A) is equivalent to one thousand milliamperes (103 mA or 1,000 mA).
What is a Milliampere?
A milliampere (mA) is a unit of electric current in the SI system equal to one thousandth (1/1,000) of an ampere (0.001 A).
Milliamps are simply amps divided by 1,000, like breaking a dollar into pennies. They’re the standard unit for devices such as phones, LED bulbs, or fitness trackers, where currents are tiny. Milliamps simplify design, troubleshooting, and documentation, keeping numbers clean and reducing errors.
A to mA formula
Let’s take a closer look at the conversion formula so you can carry out these conversions independently, whether using a calculator or doing it manually with pencil and paper.
The milli- prefix in the International System of Units (SI) represents a multiplier of 10-3 (0.001). So, to convert from amps to milliamps, multiply the number of amps (I(A)) by 1,000.
I(mA) = I(A) × 103 = I(A) × 1,000
Or remember the A-to-mA conversion factor: 1 A = 1,000 mA
A to mA conversion table
The conversion table below provides a handy reference for converting electric current measurement units from amperes (A) to milliamperes (mA). It covers a range from 0.1 A to 1,000 A, allowing for easy and quick conversions between these units of measurement.
| Amperes (A) | Milliamperes (mA) |
|---|---|
| 0.1 A | 100 mA |
| 0.5 A | 500 mA |
| 1 A | 1,000 mA |
| 2 A | 2,000 mA |
| 4 A | 4,000 mA |
| 5 A | 5,000 mA |
| 10 A | 10,000 mA |
| 20 A | 20,000 mA |
| 30 A | 30,000 mA |
| 40 A | 40,000 mA |
| 50 A | 50,000 mA |
| 60 A | 60,000 mA |
| 70 A | 70,000 mA |
| 80 A | 80,000 mA |
| 90 A | 90,000 mA |
| 100 A | 100,000 mA |
| 200 A | 200,000 mA |
| 500 A | 500,000 mA |
| 800 A | 800,000 mA |
| 1,000 A | 1,000,000 mA |
Examples
Now, let's look at an example that illustrates the calculations required to convert from amperes to milliamperes (A to mA).
Example: Smartphone Charging Systems
In smartphone battery management, charging and discharging currents are often measured in mA. Converting from amperes to mA helps engineers compare and regulate battery performance.
If a charging circuit supplies 0.85 amperes, how many milliamperes is that? You need it to calibrate the battery management system for optimal charging efficiency.
Solution
Since 1 ampere (A) = 103 = 1,000 milliamperes (mA), we can convert 0.85 A to milliamperes by using the following formula:
Therefore, the 0.85 A electric current is equivalent to 850 mA.
To solve the problem with our calculator, follow the steps below:
- Enter the value in amperes: For this example, enter
0.85 Ainto theFrombox. - View the result: The converter instantly calculates and displays the equivalent value in milliamperes:
850 mA.
FAQs
Is 1 ampere or 1 milliampere larger?
An ampere (A) is a thousand times bigger than a milliampere (mA). Here are the relationships between the units:
1 A = 103 = 1,000 mA1 mA = 10-3 = 1 ÷ 1,000 = 0.001 A
How to convert from amperes to milliamperes?
To convert electric current from amperes (A) to milliamperes (mA), follow these simple steps:
- Write down the electric current value in
amperes (A). - Multiply it by the value of a
A-to-mAconversion factor:103or1,000. - The result of multiplication is the value of the electric current in
milliamperes (mA).
Why do I need to convert amperes to milliamperes?
Converting amperes to milliamperes is essential because many everyday electronic devices and circuits operate at currents much smaller than one ampere, making measurements in milliamperes more intuitive and easier to work with.
This conversion improves clarity, simplifies calculations, and aligns with typical datasheet specifications for components like LEDs, microcontrollers, and sensors, where expressing small currents in decimals of amperes would be less practical. For example, an LED might need 0.02 amps. Saying "20 milliamps" is cleaner and faster to read than juggling decimals.
You now know how to convert electric current from amperes (A) to milliamperes (mA). You can quickly use our calculator to convert between the electric current measurement units to save time for future calculations.
