This article will show how to convert electrical resistance measurement units from milliohms (mΩ) to megaohms (MΩ). We will cover essential definitions, provide examples, share relevant formulas, and present tables, along with answers to common questions.
Definitions of Ohm, Milliohm, and Megaohm
Let’s get started by understanding the key definitions of Ohm (Ω), Milliohm (mΩ), and megaohm (MΩ). Understanding these terms will enable you to perform conversions with confidence.
What is Ohm?
The ohm (Ω) is the SI derived unit of electrical resistance. It is defined as the resistance between two points of a conductor when a constant potential difference of one volt is applied across those points, producing a current of one ampere in the conductor, assuming no additional electromotive force is present.[1]
According to SI prefixes[2], which are based on powers of 10, an ohm (1 Ω) is equivalent to one thousand milliohms (103 mΩ or 1,000 mΩ).
What is Milliohm?
A milliohm (mΩ) is a unit of electrical resistance in the SI system equal to one thousandth (1/1,000) of an ohm (10-3 Ω).
It is commonly used in fields such as power distribution, precision electronic testing, and industrial motor evaluation. Accurately measuring very low resistance values is essential for determining the efficiency and reliability of these systems.
What is Megaohm?
A megaohm (MΩ) is a unit of electrical resistance in the SI system equal to one million (1,000,000) ohms (106 Ω).
It is commonly used in high-voltage insulation testing, medical device safety validation, and industrial sensor design, where measuring extreme resistance up to millions of ohms determines critical safety margins and operational reliability.
mΩ to MΩ 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) corresponds to a multiplier of 10-3 (0.001) while the mega- prefix represents 106 (1,000,000).
To convert milliohms (mΩ) to megaohms (MΩ), divide the resistance value in milliohms by 109 (1,000,000,000), since 1 megaohm equals 1,000,000,000 milliohms.
R(MΩ) = R(mΩ) ÷ 109 = R(mΩ) ÷ 1,000,000,000
Or remember the mΩ-to-MΩ conversion factor: 1 mΩ = 10-9 = 0.000000001 MΩ
mΩ to MΩ conversion table
The conversion table below provides a handy reference for converting electrical resistance measurement units from milliohms (mΩ) to megaohms (MΩ). It covers a range from 0.1 mΩ to 1,000 mΩ, allowing for easy and quick conversions between these units of measurement.
| Milliohms (mΩ) | Megaohms (MΩ) |
|---|---|
| 0.1 mΩ | 0.0000000001 MΩ |
| 0.5 mΩ | 0.0000000005 MΩ |
| 1 mΩ | 0.000000001 MΩ |
| 2 mΩ | 0.000000002 MΩ |
| 4 mΩ | 0.000000004 MΩ |
| 5 mΩ | 0.000000005 MΩ |
| 10 mΩ | 0.00000001 MΩ |
| 20 mΩ | 0.00000002 MΩ |
| 30 mΩ | 0.00000003 MΩ |
| 40 mΩ | 0.00000004 MΩ |
| 50 mΩ | 0.00000005 MΩ |
| 60 mΩ | 0.00000006 MΩ |
| 70 mΩ | 0.00000007 MΩ |
| 80 mΩ | 0.00000008 MΩ |
| 90 mΩ | 0.00000009 MΩ |
| 100 mΩ | 0.0000001 MΩ |
| 200 mΩ | 0.0000002 MΩ |
| 500 mΩ | 0.0000005 MΩ |
| 800 mΩ | 0.0000008 MΩ |
| 1,000 mΩ | 0.000001 MΩ |
Examples
Now, let's look at an example that illustrates the calculations required to convert from milliohms to megaohms (mΩ to MΩ).
Example: Surge Protector Component Analysis
During surge protection testing, a critical component shows a very high resistance when measured in milliohms. Converting this measurement to megaohms allows for clearer reporting and easier benchmarking against specifications.
If the measured resistance is 2,500,000,000 mΩ, what is the corresponding resistance in megaohms?
Solution
Since 1 megaohm (MΩ) = 1,000,000,000 milliohms (mΩ), we can convert 2,500,000,000 mΩ to megaohms by using the following formula:
Therefore, the 2,500,000,000 mΩ electrical resistance is equivalent to 2.5 MΩ.
To solve the problem with our calculator, follow the steps below:
- Enter the value in milliohms: For this example, enter
2,500,000,000into the From box. - View the result: The converter instantly calculates and displays the equivalent value in megaohms:
2.5 MΩ.
FAQs
Is 1 milliohm or 1 megaohm larger?
A megaohm (MΩ) is a billion times bigger than a milliohm (mΩ). Here are the relationships between the units:
1 MΩ = 109 = 1,000,000,000 mΩ1 mΩ = 10-9 = 1 ÷ 1,000,000,000 = 0.000000001 MΩ
How to convert from milliohms to megaohms?
To convert electrical resistance from milliohms (mΩ) to megaohms (MΩ), follow these simple steps:
- Step 1: Write down the electrical resistance value in milliohms (mΩ).
- Step 2: Divide it by a billion (
1,000,000,000). - Step 3: The result is the value of the electrical resistance in megaohms (MΩ).
Why do I need to convert milliohms to megaohms?
Converting milliohms to megaohms is especially useful when you are dealing with extremely high resistance values that are cumbersome to express in milliohms. When measurements in milliohms involve many digits or require scientific notation, converting to megaohms offers a whole-number expression that is easier to interpret and compare.
For instance, a resistance measured at 1,000,000,000 mΩ can be expressed as 1 MΩ. This conversion reduces the complexity of the number, minimizes the risk of misinterpretation, and simplifies documentation and analysis in high-voltage and insulation testing.
You now know how to convert electrical resistance from milliohms (mΩ) to megaohms (MΩ). You can quickly use our calculator to convert between the electric resistance measurement units to save time for future calculations.
