How to Convert Microohms to Ohms
To convert an electrical resistance measurement from microohms to ohms, divide the resistance value by the conversion factor. Since one microohm is equal to 0.000001 ohms, you can use this formula:
The resistance in ohms is equal to the microohms divided by 1,000,000.
Using the formula: ohms = microohms ÷ 1,000,000
ohms = 5 µΩ ÷ 1,000,000 = 5.0000E-6 Ω
Therefore, 5 microohms equals 5.0000E-6 ohms.
How Many Ohms Are in a Microohm?
There are 0.000001 ohms in one microohm.
What Is a Microohm?
The microohm (symbol: μΩ) is a unit of electrical resistance equal to one millionth (10−6) of an ohm. The prefix “micro” denotes a factor of 10−6 in the International System of Units. Microohms are commonly used in electrical power engineering for measuring the resistance of circuit breaker contacts, transformer windings, cable joints, and other components that carry high currents. Even small resistances in the microohm range can cause significant power dissipation and heating when currents are in the hundreds or thousands of amperes. In quality control and predictive maintenance, microohm meters are used to test the contact resistance of switches, relays, and connectors. An increase in contact resistance over time can indicate deterioration, oxidation, or loose connections that could lead to failure. In metallurgy, the resistivity of metals and alloys at room temperature is often expressed in microohm-centimetres (μΩ·cm). For example, copper has a resistivity of approximately 1.72 μΩ·cm, aluminium about 2.65 μΩ·cm, and silver about 1.59 μΩ·cm.
One microohm is equal to:
- 10−6 ohms (Ω)
- 1,000 nanoohms (nΩ)
- 0.001 milliohms (mΩ)
- 1,000 abohms (abΩ)
- 1.1127 × 10−18 statohms (statΩ)
What Is a Ohm?
The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm. It is defined as the resistance between two points of a conductor when a constant potential difference of one volt applied across these points produces a current of one ampere (1 Ω = 1 V/A). The ohm is the fundamental unit for expressing electrical resistance in science and engineering worldwide. It is central to Ohm’s Law (V = IR), which relates voltage, current, and resistance in electrical circuits. In everyday electronics, resistor values span from fractions of an ohm to millions of ohms. A typical LED current-limiting resistor might be 220–470 Ω, a pull-up resistor 4,700–10,000 Ω, and the impedance of headphones 16–600 Ω. The ohm is also used to express impedance (the AC equivalent of resistance) in audio, radio frequency, and telecommunications engineering. Standard impedances include 50 Ω (RF equipment), 75 Ω (coaxial cable, video), and 8 Ω (loudspeakers). In the modern SI, the ohm is realised through the quantum Hall effect, which provides an extremely precise resistance standard. The von Klitzing constant RK = h/e² ≈ 25,812.807 Ω is used as the primary standard for resistance calibration.
One ohm is equal to:
- 1,000 milliohms (mΩ)
- 106 microohms (μΩ)
- 109 nanoohms (nΩ)
- 0.001 kiloohms (kΩ)
- 109 abohms (abΩ)
- 1.1127 × 10−12 statohms (statΩ)
Understanding Electrical Resistance Units
Electrical resistance is a measure of the opposition to the flow of electric current through a conductor. It is defined by Ohm’s law as the ratio of voltage to current (R = V/I). Resistance depends on the material’s resistivity, the length of the conductor, and its cross-sectional area (R = ρL/A).
Resistance converts electrical energy into heat, which is the basis of resistive heating in toasters, electric heaters, and incandescent light bulbs. In electronic circuits, resistors are used to control current flow, divide voltages, bias active components, and set time constants.
Major Resistance Unit Families
- SI units: The ohm (Ω) is the SI unit of resistance, with standard metric prefixes: nanoohm (nΩ = 10−9 Ω), microohm (μΩ = 10−6 Ω), milliohm (mΩ = 10−3 Ω), kiloohm (kΩ = 103 Ω), megaohm (MΩ = 106 Ω), and gigaohm (GΩ = 109 Ω).
- CGS-EMU unit: The abohm (abΩ) is the resistance unit in the electromagnetic CGS system. 1 abΩ = 10−9 Ω = 1 nΩ.
- CGS-ESU unit: The statohm (statΩ) is the resistance unit in the electrostatic CGS system. 1 statΩ ≈ 8.988 × 1011 Ω, an extremely large value reflecting the different scaling of ESU electrical quantities.
Resistance in Everyday Life
- Wiring: Household copper wiring has very low resistance (milliohms per metre) to minimise voltage drops and heating.
- Electronics: Resistors in circuits range from fractions of an ohm (current sense) to megaohms (high-impedance inputs).
- Insulation: Good electrical insulation has resistance in the megaohm to gigaohm range, preventing current leakage.
- Human body: Dry skin has a resistance of 10,000–100,000 Ω, but wet skin can be as low as 1,000 Ω, which is why water and electricity are dangerous together.
Converting Between Resistance Units
All resistance units measure the same physical quantity, so converting between them requires multiplying by the appropriate conversion factor. For SI prefixed units, each step is a factor of 1,000. The CGS units involve the speed of light constant for the statohm, while the abohm is simply 10−9 ohms.
Tips for Resistance Conversions
- For SI prefix conversions (nΩ, μΩ, mΩ, Ω, kΩ, MΩ, GΩ), each step is a factor of 1,000. So 1 kΩ = 1,000 Ω = 1,000,000 mΩ.
- The abohm is exactly equal to the nanoohm: 1 abΩ = 1 nΩ = 10−9 Ω. They’re interchangeable.
- The statohm is an enormous unit: 1 statΩ ≈ 899 GΩ. It is rarely used in modern practice.
- To convert ohms to kiloohms, divide by 1,000. To convert kiloohms to megaohms, divide by 1,000 again.
- Resistor colour codes and standard values (E-series) are always expressed in ohms. A “4.7k” resistor is 4,700 Ω = 4.7 kΩ.
- In schematics, resistance values are often shortened: 4k7 = 4.7 kΩ, 2M2 = 2.2 MΩ, 47R = 47 Ω.
- The relationship between statohm and abohm involves the speed of light squared: 1 statΩ = c² × 1 abΩ (in CGS units), or about 8.988 × 1020 abohms.
- When measuring very low resistances (milliohms and below), always use four-terminal (Kelvin) connections to eliminate lead resistance errors.
Microohms to Ohms Conversion Table
The following table shows conversions from microohms to ohms.
| Microohms | Ohms (Ω) |
|---|---|
| 1 µΩ | 1.0000E-6 |
| 2 µΩ | 2.0000E-6 |
| 3 µΩ | 3.0000E-6 |
| 4 µΩ | 4.0000E-6 |
| 5 µΩ | 5.0000E-6 |
| 6 µΩ | 6.0000E-6 |
| 7 µΩ | 7.0000E-6 |
| 8 µΩ | 8.0000E-6 |
| 9 µΩ | 9.0000E-6 |
| 10 µΩ | 1.0000E-5 |
| 11 µΩ | 1.1000E-5 |
| 12 µΩ | 1.2000E-5 |
| 13 µΩ | 1.3000E-5 |
| 14 µΩ | 1.4000E-5 |
| 15 µΩ | 1.5000E-5 |
| 16 µΩ | 1.6000E-5 |
| 17 µΩ | 1.7000E-5 |
| 18 µΩ | 1.8000E-5 |
| 19 µΩ | 1.9000E-5 |
| 20 µΩ | 2.0000E-5 |
| 21 µΩ | 2.1000E-5 |
| 22 µΩ | 2.2000E-5 |
| 23 µΩ | 2.3000E-5 |
| 24 µΩ | 2.4000E-5 |
| 25 µΩ | 2.5000E-5 |
| 26 µΩ | 2.6000E-5 |
| 27 µΩ | 2.7000E-5 |
| 28 µΩ | 2.8000E-5 |
| 29 µΩ | 2.9000E-5 |
| 30 µΩ | 3.0000E-5 |
| 31 µΩ | 3.1000E-5 |
| 32 µΩ | 3.2000E-5 |
| 33 µΩ | 3.3000E-5 |
| 34 µΩ | 3.4000E-5 |
| 35 µΩ | 3.5000E-5 |
| 36 µΩ | 3.6000E-5 |
| 37 µΩ | 3.7000E-5 |
| 38 µΩ | 3.8000E-5 |
| 39 µΩ | 3.9000E-5 |
| 40 µΩ | 4.0000E-5 |