Convert Amps to Milliamps: Equations & Explanations -
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Convert Amps to Milliamps

Converting amps to milliamps is a fairly straightforward process. While it may seem like something you only need to do if you’re an electrician, you can save yourself a lot of time and money by familirising yourself with these terms.

We know how daunting it can be to deal with these problems for the first time, so we’re here to help. 

In this article, you’ll get the necessary formula as well as some useful information about these units of measurement and what they're used for.

Once you’ve mastered this simple conversion, more complicated equations like converting volts to amps will become second nature.

Converting Amps to Milliamps

how to convert amps to milliamps

Generally speaking, when you're working with units of measurement you’re likely to come across a unit with the word ‘milli’ attached to it. This is a prefix that means one thousandth, or 1/ 1,000 of a specific value. 

No matter if you're measuring electrical current or distance, this is always the case.

How to Convert Amps to Milliamps

1 amp is equal to 1,000 milliamps. To make the amp to milliamp conversion, you need only use the following formula:

Formula: Milliamps (mA) = Amps (A) x 1,000

If you need to do the opposite and convert milliamps to amps, there is a similarly simple formula:

Formula: Amps (A) = Milliamps (mA) ÷ 1,000

Let's use an example to help you understand. For this example, we'll take one of our 40 amp solar charge controllers and convert the power rating in amps to milliamps:

40 A = 40 A x 1,000

mA = 40,000 mA

convert amp to milliamps

What Is an Amp?

An amp, which is short for amperes, is the basic unit of measurement for electric current. It measures the rate or amount of electricity flowing through an electrical circuit. The symbol for amperes is ‘A’, so one ampere would be expressed as 1 A.

If you own a solar panel kit and want to convert the wattage value to amperes for more precise calculations, all you would need to do is divide the wattage by the voltage.

convert amp to milliamp calculator

You can use these values to calculate the amp hours of a circuit or appliance.

What Is a Milliamp?

A milliamp, which is short for milliampere, is a sub-unit of measurement that’s equivalent to one 1,000th of an amp. 

This means that 1 amp is equal to 1,000 milliamps. Just like amps, milliamps are a unit of measurement for electrical current. A milliampere is abbreviated as mA, so one milliamp would be written as 1 mA.

Milliamps are used as a unit of measurement on devices such as ammeters, digital multimeters (DMM), and galvanometers. They are also used to power 4-20 mA current loops, which is a device used to measure things like pressure, temperature, and pH.

Why Do We Use Milliamps?

Milliamps are used when we are working with amps or electrical current that comes in smaller quantities. As an example, instead of saying 0.02 A, we can express the value as 20 mA instead. It's a convenient and much more precise method of measuring smaller electrical currents.

When you know how to convert milliamps to amps, you can take small appliances and figure out the amps to kilowatts, which will help you figure out your battery capacity requirements.

Milliamperes are used to measure the electrical current of devices such as cell phones and light-emitting diodes (LEDs) but are most commonly used to measure the capacity of AA batteries and mobile phone batteries.

converting amp to milliamp calculator

When used to measure the capacity of a battery, the number of milliamps is measured in milliamp hours (mAH). Milliamp hours are used to measure how much power will be available over a certain amount of time. In the case of a battery, it would be a measurement of how long said battery would be able to last.


It’s simple to convert amps to milliamps and vice versa once you understand the basics of electrical formulae.

It doesn’t stop there though. We’ve got plenty of resources on things like converting kilovolt-amps (kVA) to amps and even a wire gauge calculator so you can get the right equipment for your system.

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