How to Convert Milliohms to Statohms
To convert an electrical resistance measurement from milliohms to statohms, divide the resistance value by the conversion factor. Since one milliohm is equal to 1.1127 × 10-15 statohms, you can use this formula:
The resistance in statohms is equal to the milliohms divided by 8.9876 × 1014.
Using the formula: statohms = milliohms ÷ 8.9876 × 1014
statohms = 5 mΩ ÷ 8.9876 × 1014 = 5.5633E-15 statΩ
Therefore, 5 milliohms equals 5.5633E-15 statohms.
How Many Statohms Are in a Milliohm?
There are 1.1127 × 10-15 statohms in one milliohm.
What Is a Milliohm?
The milliohm (symbol: mΩ) is a unit of electrical resistance equal to one thousandth (10−3) of an ohm. The prefix “milli” denotes a factor of 10−3 in the International System of Units. Milliohms are used in power electronics, battery testing, and current sensing applications. The internal resistance of batteries is typically measured in milliohms — a fresh alkaline AA battery has an internal resistance of about 100–300 mΩ, while a lithium-ion cell might have 20–80 mΩ. Higher internal resistance indicates ageing or degradation. In current sensing, low-value resistors (called shunt resistors or sense resistors) in the milliohm range are placed in series with a circuit to measure current by sensing the voltage drop. Common values include 1 mΩ, 5 mΩ, 10 mΩ, and 100 mΩ. In PCB (printed circuit board) design, the resistance of copper traces carrying high currents is in the milliohm range. A 1-ounce copper trace that is 1 inch wide and 10 inches long has a resistance of approximately 5 mΩ. The resistance of fuses, circuit breaker contacts, and motor windings are also commonly measured in milliohms for quality assurance and predictive maintenance.
One milliohm is equal to:
- 0.001 ohms (Ω)
- 1,000 microohms (μΩ)
- 106 nanoohms (nΩ)
- 106 abohms (abΩ)
- 1.1127 × 10−15 statohms (statΩ)
What Is a Statohm?
The statohm (symbol: statΩ) is the unit of electrical resistance in the centimetre–gram–second electrostatic (CGS-ESU) system of units. One statohm is an extremely large unit of resistance, equal to approximately 8.988 × 1011 ohms (about 899 gigaohms). The statohm is defined from the fundamental CGS-ESU electromagnetic relations. In the ESU system, the unit of charge (statcoulomb) is defined in terms of the electrostatic force between charges, and the other electrical units follow from this. The statohm relates to the ohm through the speed of light: 1 statΩ = c² × 10−9 Ω (where c is the speed of light in CGS units). The enormous magnitude of the statohm reflects the fundamental difference in how the ESU system scales electrical quantities compared to SI. While the ESU system was historically used in electrostatics and theoretical physics, it has been entirely superseded by SI units in modern practice. The statohm occasionally appears in older theoretical physics literature and in textbooks discussing the history of electromagnetic unit systems. Understanding the relationship between the statohm and the ohm helps illustrate how different choices of fundamental constants lead to different unit magnitudes.
One statohm is equal to:
- 8.988 × 1011 ohms (Ω)
- 898.755 gigaohms (GΩ)
- 898,755 megaohms (MΩ)
- 8.988 × 108 kiloohms (kΩ)
- 8.988 × 1020 abohms (abΩ)
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.
Milliohms to Statohms Conversion Table
The following table shows conversions from milliohms to statohms.
| Milliohms | Statohms (statΩ) |
|---|---|
| 1.0000E+14 mΩ | 0.111265 |
| 2.0000E+14 mΩ | 0.22253 |
| 3.0000E+14 mΩ | 0.333795 |
| 4.0000E+14 mΩ | 0.44506 |
| 5.0000E+14 mΩ | 0.556325 |
| 6.0000E+14 mΩ | 0.66759 |
| 7.0000E+14 mΩ | 0.778855 |
| 8.0000E+14 mΩ | 0.89012 |
| 9.0000E+14 mΩ | 1.00139 |
| 1.0000E+15 mΩ | 1.11265 |
| 2.0000E+15 mΩ | 2.2253 |
| 3.0000E+15 mΩ | 3.33795 |
| 4.0000E+15 mΩ | 4.4506 |
| 5.0000E+15 mΩ | 5.56325 |
| 6.0000E+15 mΩ | 6.6759 |
| 7.0000E+15 mΩ | 7.78855 |
| 8.0000E+15 mΩ | 8.9012 |
| 9.0000E+15 mΩ | 10.0139 |
| 1.0000E+16 mΩ | 11.1265 |
| 2.0000E+16 mΩ | 22.253 |
| 3.0000E+16 mΩ | 33.3795 |
| 4.0000E+16 mΩ | 44.506 |
| 5.0000E+16 mΩ | 55.6325 |
| 6.0000E+16 mΩ | 66.759 |
| 7.0000E+16 mΩ | 77.8855 |
| 8.0000E+16 mΩ | 89.012 |
| 9.0000E+16 mΩ | 100.139 |
| 1.0000E+17 mΩ | 111.265 |