Voltage

Voltage Converter

Details

How to use Voltage Converter

What the tool does, how to run it, and what to expect from the result.

How to convert voltage units

Enter a voltage, pick the unit it is in, and pick the unit you want. Microvolts, millivolts, volts and kilovolts all update at once, which is useful when a datasheet mixes scales inside one table.

The volt is the internal base and every step is a clean power of 1,000. Keep in mind that AC values are conventionally RMS, and that this page converts units rather than waveform statistics.

  • Type the voltage in the Value box, for example 1.024.
  • Pick the From unit, for example Volt (V).
  • Pick the To unit, for example Millivolt (mV).
  • Read the result and the full table for the microvolt and kilovolt ends.
  • If you need a peak value from an RMS one, multiply by 1.41421 before or after converting.

RMS, peak, and peak-to-peak are three different numbers

An AC voltage has no single value, so the industry picked one convention: quoted figures are RMS, the equivalent DC voltage that would deliver the same heating power. Mains described as 230 V or 120 V is RMS. The peak of that same sine wave is RMS times the square root of two, and the peak-to-peak swing is twice the peak again.

This page scales units, not waveform statistics. If you enter 230 and read millivolts, you get 230,000 mV of RMS, not of peak. Do the square-root-of-two step yourself, in either order, since multiplying by 1.41421356 and dividing by 1,000 commute. On an oscilloscope the trap runs the other way: the scope shows peak-to-peak, and dividing by 2.828 gets you back to the RMS figure a datasheet would quote.

  • RMS to peak: multiply by 1.41421356 (sine waves only).
  • Peak to peak-to-peak: multiply by 2.
  • Peak-to-peak to RMS: divide by 2.82842712 (sine waves only).

From microvolts to kilovolts in one table

The four units on this page cover nine orders of magnitude, which sounds excessive until you notice how often one project spans them. A thermocouple front end works in microvolts, its amplifier output in millivolts, the logic rail feeding the ADC in volts, and the machine it is bolted to may sit on a kilovolt supply.

Because every step is a factor of a thousand, conversions here are just decimal shifts and cannot introduce rounding error. That is not true of most unit families on this site, and it is why voltage figures in a report can be quoted in whichever unit keeps the number readable without any loss of precision.

Tips

Getting a better result out of Voltage Converter

Specific settings and thresholds, not general advice.

  • The whole ladder is powers of 1,000: 1 kV is 1,000 V, 1,000,000 mV, and 1,000,000,000 microvolts.
  • AC mains figures are RMS, not peak. 230 V RMS peaks at 325.269119346 V, and 120 V RMS peaks at 169.705627485 V. This tool converts the number you type, it does not apply the square root of 2.
  • Sensor outputs live at the small end: a type-K thermocouple produces roughly 41 microvolts per degree Celsius, which is 0.041 mV, and that is why thermocouple amplifiers exist.
  • Logic rails are usually stated in volts and measured in millivolts: a 3.3 V rail is 3,300 mV, and an ADC reading of 1,024 mV is 1.024 V.
  • Transmission lines run at 110 kV to 765 kV, which is 110,000 V to 765,000 V, twelve orders of magnitude above the microvolt end of the same table.
Limits

What Voltage Converter does not do

The honest boundary, so you do not lose time finding it yourself.

  • No RMS, peak, or peak-to-peak conversion for AC waveforms.
  • No decibel units (dBV, dBu, dBm).
  • No Ohm's law. It cannot get volts from amps and ohms, or watts from volts and amps.
  • One value at a time, and no waveform or signal input.
At a glance

Who Voltage Converter is for

A quick way to understand who this helps, what it solves, and where it connects next.

Best fit

Students, engineers, developers, makers, and anyone who needs a quick, accurate voltage conversion.

Ideal for

Fast, reliable voltage conversions without installing an app or trusting a server with your numbers.

FAQ

Common questions

Short answers for the questions people usually have before trying a utility like this.

Does my data get uploaded anywhere?

No. Everything runs locally in your browser and nothing is sent to a server.

Is this free to use?

Yes. It is completely free, with no account, no signup, and no usage limits.

Does it work on a phone?

Yes. The page runs in any modern mobile browser, on iPhone and Android alike, with no app to install.

What is the peak voltage of 230 V AC?

325.27 V, because the quoted 230 V is an RMS value and the peak of a sine wave is RMS times the square root of 2 (1.41421). The converter does not do that step, it only scales between microvolts, millivolts, volts and kilovolts.

How do I convert a millivolt ADC reading into volts?

Divide by 1,000, or enter the reading with Millivolt selected and read the Volt row. A 1,024 mV reading is 1.024 V. Enter the value once and the whole table, including microvolts, updates with it.

Where is kV used outside power lines?

X-ray tubes run at 80 to 140 kV, electron microscopes at 30 to 300 kV, and old CRT anodes at around 25 kV. Any of these is a plain multiplication by 1,000 from volts, which is what this page does.

Can this converter apply Ohm's law?

No. Ohm's law needs two of voltage, current and resistance to give you the third, and this page has only voltage units. Use the Current Converter for the amps side and do the multiplication or division yourself.

Why is the microvolt written with a Greek mu?

Micro is the SI prefix for one millionth, and its symbol is the Greek letter mu. So 1 microvolt is 0.000001 V, and the tool prints it as the mu symbol followed by V in the unit list.

How many millivolts are in a volt?

Exactly 1,000, and the same factor applies at every step: 1,000 microvolts to a millivolt, 1,000 volts to a kilovolt. A 3.3 V rail is 3,300 mV and 3,300,000 µV, so converting here never introduces rounding, it only moves the decimal point.

Can I convert volts to watts or amps here?

No, and no converter can do it from a voltage alone. Watts need volts times amps, and amps need volts divided by ohms, so you must supply the second quantity. Convert the voltage units here, then use the Current Converter or the Power Converter for the other side and do the multiplication yourself.

What is a millivolt used for?

It is the working unit for anything measured rather than supplied: ADC readings, sensor outputs, battery cell deltas, and offset voltages in op-amp datasheets. A single-cell lithium pack sitting at 3,850 mV is easier to compare against a 3,900 mV sibling than the same values written as volts.

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