Voltage Converter
Convert between voltage units: volts, millivolts, kilovolts and more, instantly. No signup. Ideal for electronics, engineering, science and technical work.
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This voltage converter turns any voltage between units, volts, millivolts, kilovolts and more, directly in your browser. Enter a value and its unit, and see the equivalent in others. No account, no install, so you can convert voltages for electronics, engineering and science on any device in seconds.
How to Convert Voltage Units Step by Step
- Enter the voltage. Type the voltage value you want to convert into the input field, such as a reading or a specification from a datasheet.
- Choose the starting unit. Select the unit your voltage is in, whether volts, millivolts, kilovolts, or another voltage unit with its prefix.
- Convert to other units. The tool converts your voltage into the other units, showing the equivalent values so you can see it expressed with whichever prefix you need.
- Read the equivalents. See your voltage in the relevant units at once, letting you understand and compare it across the small and large voltage units.
- Use the converted value. Apply the converted voltage to your electronics, engineering, or science task, working in whichever unit suits your context.
What Voltage Is and How It Is Measured
Voltage, the electrical potential difference that drives current, is measured in volts, but the volt is used with a range of prefixes to express very small and very large voltages conveniently. Millivolts express small voltages, kilovolts express large ones, and other prefixes cover the range in between and beyond. These prefixed units are all just scaled versions of the volt, related by powers of ten.
The prefixes work exactly as in the wider metric system, each representing a power of ten. A millivolt is a thousandth of a volt, a kilovolt is a thousand volts, and so on. This lets a huge range of voltages, from tiny signals to high power levels, be expressed in convenient numbers rather than very large or very small figures in plain volts. Converting between the prefixed units is simply a matter of the powers of ten.
Because the units relate by powers of ten, converting is straightforward in principle, but it is easy to slip by a factor of a thousand or misplace a decimal point when doing it in your head, especially across several prefixes. A voltage converter handles the scaling exactly, avoiding the errors that come from mentally juggling the prefixes, which matters in electronics and engineering where accuracy is important.
Voltage conversion is needed in electronics, electrical engineering and science, wherever voltages are worked with across different scales. A datasheet might specify a voltage in millivolts while your calculation uses volts, or a high voltage might be given in kilovolts. Converting between the units lets you work consistently and understand values given with different prefixes. A converter gives quick, accurate results for any voltage in any unit.
Why the Prefixes Matter
| Unit | Relation to the volt | Used for |
|---|---|---|
| Millivolt | A thousandth of a volt | Small voltages, signals |
| Volt | The base unit | Everyday voltages |
| Kilovolt | A thousand volts | High voltages |
| The prefixes | Powers of ten | Convenient across scales |
Who Uses a Voltage Converter
Pro Tips for Voltage Conversions
Common Voltage Conversion Mistakes to Avoid
Related Tools You May Need Next
For other unit conversions, our Length Converter, Temperature Converter and Pressure Converter help. For general calculations, the Scientific Calculator is available.
Frequently Asked Questions
How do I convert between voltage units?
Enter your voltage value and select its unit, whether volts, millivolts, kilovolts or another, and the tool converts it into the other units, showing the equivalent values. Since the voltage units are the volt scaled by metric prefixes, related by powers of ten, the converter applies the correct scaling exactly. This lets you express a voltage with whichever prefix you need and saves you from mentally juggling the powers of ten, which is easy to get wrong, especially across several prefixes or a wide range of values.
What is voltage and how is it measured?
Voltage is the electrical potential difference that drives current in a circuit. It is measured in volts, the base unit, but the volt is used with a range of metric prefixes to express very small and very large voltages conveniently. Millivolts express small voltages, such as signals, kilovolts express large ones, such as high power levels, and other prefixes cover the range between and beyond. These prefixed units are all scaled versions of the volt, related by powers of ten, letting a huge range of voltages be expressed in convenient numbers.
Why does voltage use prefixes like milli and kilo?
Because voltages span an enormous range, from tiny signals to very high power levels, and prefixes let this range be expressed in convenient numbers. Rather than writing very small or very large figures in plain volts, the metric prefixes scale the volt: a millivolt is a thousandth of a volt, a kilovolt is a thousand volts, and so on. Each prefix represents a power of ten, exactly as in the wider metric system. This makes voltages across all scales easy to express and work with, which is why voltage is commonly given with these prefixes.
How do the voltage units relate to each other?
The voltage units are all the volt scaled by metric prefixes, related by powers of ten. A millivolt is a thousandth of a volt, a kilovolt is a thousand volts, and other prefixes represent their own powers of ten. So converting between them is a matter of shifting by the appropriate power of ten. This is straightforward in principle, but because the factors are powers of ten, it is easy to slip by a factor of a thousand or misplace a decimal point when converting mentally, which is why a converter that applies the scaling exactly is useful.
Why is it easy to make errors converting voltage?
Because the units relate by powers of ten, and converting involves shifting the decimal point by the appropriate power. It is easy to slip by a factor of a thousand, such as confusing millivolts and volts, or to misplace the decimal point, especially when converting across several prefixes or a wide range of values. These mistakes give wildly wrong results. This is why a voltage converter is valuable: it handles the scaling exactly, avoiding the factor and decimal errors that come from mentally juggling the prefixes, which matters where voltage accuracy is important.
Who needs to convert voltage units?
Voltage conversion is needed in electronics, electrical engineering and science, wherever voltages are worked with across different scales. Electronics hobbyists and engineers convert between units like millivolts and volts when working with signals and components. Electrical engineers convert between volts and kilovolts across the range of voltages in power and systems. Students convert voltage units in their calculations. Anyone reading a datasheet that specifies a voltage in a different prefix than their work uses converts it for consistency. A converter serves all these needs with quick, accurate results.
Should I convert datasheet voltages to my working unit?
Yes, it is a good idea to convert voltages given in datasheets to the unit your calculation or design uses, so all your values are consistent. Datasheets may specify voltages in a different prefix, such as millivolts, than the volts your work uses. Converting them to your working unit ensures your calculation uses a single, consistent scale, avoiding the errors that come from mixing units. So when a specification gives a voltage in an unfamiliar prefix, convert it to your working unit before incorporating it, keeping your work accurate and consistent.
Is the voltage converter free?
Yes, it is completely free with no account and no usage limit. You can convert as many voltages between units as you like, as often as you like, at no cost. It runs entirely in your browser on any device, so there is nothing to download or install, and the equivalent voltages in other units appear instantly whenever you enter a value and choose its unit, helping with electronics, engineering, science and technical voltage conversions.