Convert Voltage Units Instantly Convert between volts, millivolts, microvolts, kilovolts, and megavolts.

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Voltage Converter

Convert between volts, millivolts, microvolts, kilovolts, and megavolts.

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What Is Voltage Converter?

A voltage converter translates between different scales of the volt, the SI derived unit of electric potential difference. One volt is the potential difference that drives one ampere of current through one ohm of resistance (V = IR). Millivolts (mV) and microvolts (µV) are used for sensor signals and biomedical measurements (ECG, EEG). Kilovolts (kV) are used for power transmission and high-voltage equipment. Megavolts (MV) appear in particle accelerators and lightning research. This converter covers the full practical range of voltage measurements.

Why Use Voltage Converter?

Covers µV to MV — the full practical voltage range.
Essential for electronics and electrical engineering.
Real-time bidirectional conversion.
Quick reference for common voltage levels.

Common Use Cases

Electronics

Convert between mV and V for sensor signals and analog circuits.

Power Systems

Translate V to kV when reviewing power transmission specifications.

Biomedical

Switch between µV and mV readings for ECG, EEG, and other biosignal data.

High-Voltage Engineering

Work with kV and MV specifications for transformers and accelerators.

Technical Guide

The volt (V) is defined as the potential difference across a conductor when 1 ampere dissipates 1 watt of power: V = W/A = kg·m²/(A·s³).

• 1 MV = 1,000 kV = 1,000,000 V
• 1 kV = 1,000 V
• 1 V = 1,000 mV = 1,000,000 µV

Common voltages:
• EEG brain signal: 10-100 µV
• AA battery: 1.5 V
• USB: 5 V
• US household: 120 V (RMS)
• EU household: 230 V (RMS)
• Power lines: 110-765 kV
• Lightning: 100-300 MV

Tips & Best Practices

1
US household: 120V. European household: 230V.
2
Sensor signals are often in mV or µV — precision amplification is needed.
3
Power line voltages are in kV to reduce transmission losses (P = I²R).
4
Lightning can reach 100-300 million volts (100-300 MV).

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Frequently Asked Questions

Q How many millivolts in a volt?

Exactly 1,000 millivolts (mV) equal one volt (V).

Q Why is power transmitted at high voltage?

Higher voltage allows the same power to be transmitted with lower current (P = VI), which reduces resistive losses (P_loss = I²R). This is why power lines use 100+ kV.

Q What voltage is a car battery?

A car battery is nominally 12V (12.6V fully charged). The charging system operates at about 14V.

Q What is the difference between AC and DC voltage?

DC voltage is constant. AC voltage alternates direction — household 120V/230V is the RMS (root mean square) value; the peak is about 1.414× higher.

About This Tool

Voltage Converter is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.