How to Convert Volts to Millivolts
To convert a voltage measurement from volts to millivolts, multiply the voltage by the conversion factor. Since one volt is equal to 1,000 millivolts, you can use this formula:
The voltage in millivolts is equal to the volts multiplied by 1,000.
Using the formula: millivolts = volts × 1,000
millivolts = 5 V × 1,000 = 5,000 mV
Therefore, 5 volts equals 5,000 millivolts.
How Many Millivolts Are in a Volt?
There are 1,000 millivolts in one volt.
What Is a Volt?
The volt (symbol: V) is the SI derived unit of electric potential, electric potential difference (voltage), and electromotive force (EMF). It is named after the Italian physicist Alessandro Volta, who invented the first chemical battery (the voltaic pile) in 1800. The volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power (1 V = 1 W/A = 1 J/C). Equivalently, one volt is the potential difference that will move one coulomb of charge through one joule of energy. Volts are the standard unit for expressing voltage in virtually all electrical and electronic applications. Common voltages include: USB power at 5 V, car batteries at 12 V, household mains at 120 V (US) or 230 V (Europe), and high-voltage transmission lines at 110–765 kV. In everyday life, AA and AAA batteries provide 1.5 V, a 9 V battery powers smoke detectors, and a smartphone battery operates at 3.7–4.2 V. Static electricity from walking on carpet can generate 1,000–25,000 V, though at negligible current.
One volt is equal to:
- 1,000 millivolts (mV)
- 106 microvolts (μV)
- 109 nanovolts (nV)
- 0.001 kilovolts (kV)
- 10−6 megavolts (MV)
- 0.003336 statvolts (stV)
- 108 abvolts (abV)
What Is a Millivolt?
The millivolt (symbol: mV) is a unit of electric potential equal to one thousandth (10−3) of a volt. The prefix “milli” denotes a factor of 10−3 in the International System of Units. Millivolts are commonly encountered in sensor technology, biomedical engineering, and thermoelectric measurements. Thermocouples generate voltage outputs in the millivolt range: a type K thermocouple produces approximately 41 μV per °C, giving about 4.1 mV for a 100 °C temperature difference. In electrochemistry, electrode potentials and the voltage outputs of pH meters and ion-selective electrodes are often in the millivolt range. A standard pH electrode produces approximately 59.2 mV per pH unit at 25 °C (the Nernst slope). Solar cells generate open-circuit voltages of several hundred millivolts per cell (typically 500–700 mV for silicon cells). In audio, line-level signals are typically 300 mV to 2 V, while headphone signals may be 100–500 mV.
One millivolt is equal to:
- 0.001 volts (V)
- 1,000 microvolts (μV)
- 106 nanovolts (nV)
- 10−6 kilovolts (kV)
- 3.3356 × 10−6 statvolts (stV)
- 105 abvolts (abV)
Understanding Voltage Units
Voltage (also called electric potential difference or electromotive force) is a measure of the work needed to move a unit electric charge from one point to another in an electric field. It is one of the most fundamental quantities in electricity and electronics, analogous to pressure in a water system.
Ohm’s law (V = I × R) relates voltage (V) to current (I) and resistance (R), and the power equation (P = V × I) connects voltage to electrical power. These relationships are the foundation of all electrical engineering.
Major Voltage Unit Systems
- SI units (V with metric prefixes): The volt (V) is the SI derived unit of electric potential. Standard metric prefixes produce nanovolts (nV), microvolts (μV), millivolts (mV), kilovolts (kV), megavolts (MV), and gigavolts (GV). Each prefix step is a factor of 1,000.
- CGS electrostatic unit — Statvolt (stV): The voltage unit in the Gaussian/ESU system. One statvolt equals exactly 299.792458 V, a factor derived from the speed of light. Used in some theoretical physics contexts.
- CGS electromagnetic unit — Abvolt (abV): The voltage unit in the EMU system. One abvolt equals exactly 10−8 V (10 nanovolts). An extremely small unit, primarily of historical interest.
Voltage in Everyday Life
- Batteries: AA/AAA cells = 1.5 V, 9 V battery, car battery = 12 V, smartphone = 3.7–4.2 V.
- Household mains: 120 V (North America, Japan) or 230 V (Europe, Asia, Africa) at 50 or 60 Hz AC.
- USB power: USB 2.0/3.0 = 5 V, USB-C PD = 5/9/15/20 V (up to 48 V in Extended Power Range).
- Power transmission: 110–765 kV for long-distance lines, 4–35 kV for local distribution.
- Lightning: 100–300 MV potential difference, 20,000–200,000 A peak current.
- Static electricity: Walking on carpet can generate 1–25 kV.
Converting Between Voltage Units
SI voltage conversions follow simple powers of 10: each metric prefix step (nano → micro → milli → base → kilo → mega → giga) is a factor of 1,000. For CGS units, the key factors are: 1 stV = 299.792458 V (from the speed of light) and 1 abV = 10−8 V (exact).
Tips for Voltage Conversions
- For SI prefix conversions (nV, μV, mV, V, kV, MV, GV), each step is a factor of 1,000. So 1 kV = 1,000 V = 1,000,000 mV, and 1 V = 1,000 mV = 1,000,000 μV.
- The statvolt factor (299.792458 V) comes from the speed of light: c = 299,792,458 m/s, and 1 stV = c/(106) V. This is an exact value.
- The abvolt is exactly 10 nanovolts (10−8 V). This is a very small voltage — it takes 100 million abvolts to make 1 volt.
- The relationship between statvolts and abvolts involves c²: 1 stV = c² × 10−8 abV ≈ 2.998 × 1010 abV.
- When dealing with very large or very small numbers, scientific notation is helpful: 1 GV = 109 V, and 1 nV = 10−9 V.
- Don’t confuse voltage (electric potential, measured in volts) with current (charge flow, measured in amperes) or resistance (opposition to current, measured in ohms). Voltage “pushes” current through resistance.
- In practice, kilovolts are the most common “large” voltage unit (power lines, X-rays), while millivolts and microvolts are common “small” units (sensors, biomedical signals).
Volts to Millivolts Conversion Table
The following table shows conversions from volts to millivolts.
| Volts | Millivolts (mV) |
|---|---|
| 1 V | 1,000 |
| 2 V | 2,000 |
| 3 V | 3,000 |
| 4 V | 4,000 |
| 5 V | 5,000 |
| 6 V | 6,000 |
| 7 V | 7,000 |
| 8 V | 8,000 |
| 9 V | 9,000 |
| 10 V | 10,000 |
| 11 V | 11,000 |
| 12 V | 12,000 |
| 13 V | 13,000 |
| 14 V | 14,000 |
| 15 V | 15,000 |
| 16 V | 16,000 |
| 17 V | 17,000 |
| 18 V | 18,000 |
| 19 V | 19,000 |
| 20 V | 20,000 |
| 21 V | 21,000 |
| 22 V | 22,000 |
| 23 V | 23,000 |
| 24 V | 24,000 |
| 25 V | 25,000 |
| 26 V | 26,000 |
| 27 V | 27,000 |
| 28 V | 28,000 |
| 29 V | 29,000 |
| 30 V | 30,000 |
| 31 V | 31,000 |
| 32 V | 32,000 |
| 33 V | 33,000 |
| 34 V | 34,000 |
| 35 V | 35,000 |
| 36 V | 36,000 |
| 37 V | 37,000 |
| 38 V | 38,000 |
| 39 V | 39,000 |
| 40 V | 40,000 |