How to Convert Statfarads to Millifarads
To convert a capacitance measurement from statfarads to millifarads, divide the capacitance value by the conversion factor. Since one statfarad is equal to 1.1126 × 10-9 millifarads, you can use this formula:
The capacitance in millifarads is equal to the statfarads divided by 8.9876 × 108.
Using the formula: millifarads = statfarads ÷ 8.9876 × 108
millifarads = 5 stF ÷ 8.9876 × 108 = 5.5632E-9 mF
Therefore, 5 statfarads is equal to 5.5632E-9 millifarads.
How Many Millifarads Are in a Statfarad?
There are 1.1126 × 10-9 millifarads in one statfarad, which is why we use this value in the formula above.
What Is a Statfarad?
The statfarad (symbol: stF) is the unit of electrical capacitance in the centimetre–gram–second (CGS) electrostatic system of units. It is defined as the capacitance of a capacitor that has a potential difference of one statvolt when charged by one statcoulomb of electricity. One statfarad is approximately equal to 1.1126 picofarads (1.1126 × 10−¹² farads). This makes the statfarad a very small unit of capacitance, though it is much more practically sized than the farad for describing the capacitances of small components. The conversion factor between farads and statfarads is derived from the speed of light in vacuum (c ≈ 2.998 × 10¹&sup0; cm/s), as the relationship between SI and CGS electrostatic units depends on this fundamental constant. Specifically, 1 farad = c² × 10−&sup5; statfarads ≈ 898,755,224,014.74 statfarads. Like the abfarad, the statfarad is primarily of historical and theoretical interest. It appears in older physics literature using the CGS electrostatic system. Modern practice favors SI units for all capacitance measurements, though understanding CGS units remains important for reading historical scientific papers.
One statfarad is equal to:
- ≈ 1.1126 × 10-12 farads (F)
- ≈ 1.1126 × 10-9 millifarads (mF)
- ≈ 1.1126 × 10-6 microfarads (μF)
- ≈ 0.001113 nanofarads (nF)
- ≈ 1.1126 picofarads (pF)
- ≈ 1.1126 × 10-21 abfarads (abF)
What Is a Millifarad?
The millifarad (symbol: mF) is a unit of electrical capacitance equal to one thousandth (10−³) of a farad. The prefix "milli" comes from the Latin "mille" meaning thousand, and in the metric system it denotes a factor of one thousandth. While the millifarad is less commonly used than microfarads or picofarads in everyday electronics, it serves as a convenient intermediate unit. Values in the millifarad range are encountered in power supply filtering, audio crossover networks, and some energy storage applications. Supercapacitors and certain electrolytic capacitors used in power electronics may have capacitances expressed in millifarads. For example, a large electrolytic capacitor rated at 10,000 μF could equivalently be expressed as 10 mF. The millifarad is part of the International System of Units (SI) and maintains the same fundamental definition as the farad, just scaled by a factor of 10−³.
One millifarad is equal to:
- 0.001 farads (F)
- 1,000 microfarads (μF)
- 1,000,000 nanofarads (nF)
- 1,000,000,000 picofarads (pF)
- 10-12 abfarads (abF)
- 898,755,224.01 statfarads (stF)
Understanding Capacitance
Capacitance is a fundamental electrical property that describes a component's ability to store electrical energy in an electric field. A capacitor, the component that exhibits capacitance, consists of two conductive plates separated by an insulating material called a dielectric.
When a voltage is applied across a capacitor, positive charge accumulates on one plate and negative charge on the other, creating an electric field in the dielectric. The capacitance (C) is defined as the ratio of the electric charge (Q) stored on each plate to the voltage (V) across the capacitor: C = Q / V.
The SI unit of capacitance is the farad (F), named after Michael Faraday. One farad equals the capacitance when one coulomb of charge produces one volt of potential difference. In practice, a farad is an extremely large unit, so capacitance values in electronic circuits are typically expressed in sub-multiples: millifarads (mF), microfarads (μF), nanofarads (nF), and picofarads (pF).
SI vs. CGS Units
The International System of Units (SI) uses the farad and its metric prefixed sub-multiples. The older centimetre–gram–second (CGS) system includes two capacitance units: the abfarad (from the electromagnetic sub-system, equal to 10&sup9; farads) and the statfarad (from the electrostatic sub-system, approximately 1.1126 × 10−¹² farads).
While CGS units are largely obsolete in modern engineering, they still appear in some physics textbooks and older scientific literature. Understanding the conversion between these systems is important for interpreting historical data and theoretical calculations.
Factors Affecting Capacitance
- Plate area — Larger plate area increases capacitance
- Distance between plates — Smaller separation increases capacitance
- Dielectric material — Higher dielectric constant (κ) increases capacitance
- Temperature — Can affect the dielectric constant and thus capacitance
Common Capacitance Values in Electronics
- Supercapacitors: 0.1 F to 3,000+ F
- Electrolytic capacitors: 0.1 μF to 100,000 μF
- Film capacitors: 1 nF to 100 μF
- Ceramic capacitors: 1 pF to 100 μF
- Trimmer/variable capacitors: 1 pF to 500 pF
Practical Tips for Capacitance Conversion
- When working with SI capacitance units (F, mF, μF, nF, pF), remember that each step is a factor of 1,000: 1 F = 1,000 mF = 1,000,000 μF = 1,000,000,000 nF = 1,000,000,000,000 pF.
- To convert between adjacent SI prefix levels, simply move the decimal point three places. For example, 4,700 pF = 4.7 nF = 0.0047 μF.
- Capacitor markings on small components (like ceramic capacitors) are often in picofarads using a three-digit code. The first two digits are significant figures and the third is the multiplier (number of zeros). For example, "473" means 47,000 pF = 47 nF.
- When reading schematics, pay close attention to the unit prefix. Confusing μF and nF (a factor of 1,000 difference) is a common source of circuit errors.
- For CGS units (abfarads and statfarads), remember that 1 abfarad = 10&sup9; F is enormous, while 1 statfarad ≈ 1.1126 pF is tiny. These units are rarely used in modern practice.
- Online calculators and conversion tools are helpful, but always double-check critical calculations by hand, especially for precision applications in filter design or timing circuits.
Statfarads to Millifarads Conversion Table
The following table shows conversions from statfarads to millifarads.
| Statfarads | Millifarads (mF) |
|---|---|
| 1.0000E+8 stF | 0.111265 |
| 2.0000E+8 stF | 0.22253 |
| 3.0000E+8 stF | 0.333795 |
| 4.0000E+8 stF | 0.44506 |
| 5.0000E+8 stF | 0.556325 |
| 6.0000E+8 stF | 0.66759 |
| 7.0000E+8 stF | 0.778855 |
| 8.0000E+8 stF | 0.89012 |
| 9.0000E+8 stF | 1.00138 |
| 1.0000E+9 stF | 1.11265 |
| 1.0000E+9 stF | 1.11265 |
| 2.0000E+9 stF | 2.2253 |
| 3.0000E+9 stF | 3.33795 |
| 4.0000E+9 stF | 4.4506 |
| 5.0000E+9 stF | 5.56325 |
| 6.0000E+9 stF | 6.6759 |
| 7.0000E+9 stF | 7.78855 |
| 8.0000E+9 stF | 8.9012 |
| 9.0000E+9 stF | 10.0138 |
| 1.0000E+10 stF | 11.1265 |
| 1.0000E+10 stF | 11.1265 |
| 2.0000E+10 stF | 22.253 |
| 3.0000E+10 stF | 33.3795 |
| 4.0000E+10 stF | 44.506 |
| 5.0000E+10 stF | 55.6325 |
| 6.0000E+10 stF | 66.759 |
| 7.0000E+10 stF | 77.8855 |
| 8.0000E+10 stF | 89.012 |
| 9.0000E+10 stF | 100.138 |
| 1.0000E+11 stF | 111.265 |