Voltage Unit Scale Converter

Electromotive Force & SI Metric Voltage Hierarchy

Voltage is the work required per unit charge to move a test charge between two points in a static electric field.

Voltage Scales Across Science & Technology

• Nanovolts (nV, 10^-9 V): Ultra-sensitive SQUID magnetometers, cryogenic Johnson noise thermometry, and deep-space radio astronomy receivers.

• Microvolts (μV, 10^-6 V): Human electroencephalogram (EEG) signals (10–100 µV), thermocouple temperature sensors, and high-gain audio preamps.

• Millivolts (mV, 10^-3 V): Human electrocardiogram (ECG) cardiac peaks (~1 mV), cellular nerve action potentials (~70–100 mV), and dynamic microphone outputs.

• Volts (V): USB-C power delivery (5V to 48V), automotive lithium/lead batteries (12V–48V), digital logic rails (1.8V, 3.3V, 5V), and residential grid power.

• Kilovolts (kV, 10^3 V): Automotive spark plugs (15–30 kV), medical X-ray vacuum tubes (40–150 kV), and utility distribution power lines (4 kV to 35 kV).

• Megavolts (MV, 10^6 V): High-Voltage Direct Current (HVDC) cross-country grids (500 kV to 1,100 kV) and natural lightning discharge arcs (100–300 MV).

How to Use This Calculator

Enter your Voltage Value (e.g. 120), Input Voltage Unit — choose from Nanovolts (nV, 10⁻⁹ V), Microvolts (µV, 10⁻⁶ V), Millivolts (mV, 10⁻³ V), and Electrical / Engineering Context — choose from AC Mains / Residential Utility (120V / 230V), Automotive / 12V-48V DC Systems, Microelectronics / Logic (1.8V, 3.3V, 5.0V). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Voltage (V) represents electric potential difference and electromotive force:1 Volt (V) = 1(Joule) / (Coulomb) = 1(Watt) / (Ampere) SI prefix scaling ratios:- 1 nV = 10^-9 V- 1\ μV = 10^-6 V- 1 mV = 10^-3 V- 1 kV = 10^3 V = 1,000 V- 1 MV = 10^6 V = 1,000,000 V decibel-volt relationships: = 20 _10((V) / (1 V)), dBμV = 20 _10((V) / (10^-6) V)

Worked Example

For example, converting residential mains electricity of 120 V: . For an EEG brain wave signal of 50\ μV: .

Understanding Your Result

Unit conversions are exact by definition within a given measurement system (e.g., 1 km = exactly 1,000 m). Cross-system conversions (metric to imperial) use defined exchange factors: 1 inch = exactly 2.54 cm; 1 pound = 0.45359237 kg. Round your converted result to match the precision of your original measurement — expressing more decimal places than your input justifies implies false accuracy. For regulatory, legal, or safety-critical applications, verify which measurement system is required by the applicable standard.