Voltage Converter
Convert between volt, millivolt, kilovolt, and megavolt instantly.
Enter any value and all units update automatically with a quick voltage reference table.
Type in any field — the others update instantly.
Voltage is the difference in electrical potential between two points, the push that drives current through a circuit. The usual analogy is water pressure: voltage is the pressure, current is the flow. The SI unit is the volt (V), and it covers an enormous range in ordinary life.
Metric prefixes:
- 1 V = 1,000 mV (millivolts)
- 1 kV = 1,000 V (kilovolts)
- 1 MV = 1,000,000 V (megavolts)
Voltages you meet:
- AA battery: 1.5 V
- USB charging: 5 V
- US household outlet: 120 V
- EU household outlet: 230 V
- High-voltage transmission line: 110–765 kV
Voltage is what decides whether current can force its way through a given resistance, including you. Dry skin blocks current well at low voltage, which is why a 9 V battery on your tongue tingles but the same battery in your hand does nothing. At hundreds of volts that protection breaks down and current flows freely, which is the real hazard of mains and transmission lines.
One subtlety worth carrying around: an AC voltage has two numbers. The “120 V” or “230 V” on your outlet is the RMS value, the effective figure used for power. The actual peak swings about 1.41 times higher, near 170 V or 325 V. Insulation and components have to survive the peak, not the RMS, so that distinction is more than academic.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.