Farad to Millifarad Converter
Quickly convert from Farad to Millifarad.
How to convert
Formula:
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Capacitance conversion is key in electronics design, where capacitors filter noise, store energy, and control timing.
Where is it used?
• Power Supplies — Electrolytic capacitors (100 μF to 10,000 μF) filter ripple in DC power supplies.
Examples:
• 1 F (farad) = 1,000,000 μF
• 1 μF = 1,000 nF
Capacitance measures how much electric charge a component can store at a given voltage, making it central to filtering, timing, decoupling, and energy-buffering in electronic systems. Engineers routinely convert between farads, microfarads, nanofarads, and picofarads across 12 orders of magnitude, from ~10 pF RF matching capacitors to multi-farad supercapacitors in backup and pulse-power applications.
Capacitance measures a component's ability to store electric charge. The SI unit is the farad (F), defined as the capacitance that stores 1 coulomb of charge with 1 volt across it. One farad is enormous in practice — most capacitors are in microfarads (μF = 10⁻⁶ F), nanofarads (nF = 10⁻⁹ F), or picofarads (pF = 10⁻¹² F).
Where is it used?
- Power Supplies — Electrolytic capacitors (100 μF to 10,000 μF) filter ripple in DC power supplies.
- RF & High-Frequency Circuits — Ceramic capacitors (1 pF to 100 nF) decouple power supply pins and filter RF noise.
- Timing Circuits — RC circuits use capacitors to set time constants: τ = R × C. A 100 kΩ resistor with 10 μF capacitor gives τ = 1 second.
- Audio — Coupling capacitors (1-100 μF) block DC while passing audio signals; tone control networks use nF-range capacitors.
- Energy Storage — Supercapacitors (1 F to 3,000 F) used in regenerative braking, UPS systems, and burst-power applications.
- Memory & Pulse Electronics — DRAM cells store bits as charge in tiny capacitors, while camera flashes, defibrillators, and pulsed-laser systems discharge capacitor banks rapidly to deliver short bursts of energy.
Common Conversion Mistakes
Confusing μF, nF, and pF scale
1 μF = 1,000 nF = 1,000,000 pF. A circuit calling for 100 nF and receiving 100 μF will malfunction — 1,000× too much capacitance. Always verify the unit when reading component values.
Ignoring voltage rating
A 100 μF capacitor rated 16 V will fail (often explosively) if placed in a 24 V circuit. Always use capacitors rated at least 20-50% above the expected voltage. Electrolytic capacitors are polarized and will also fail if connected backwards.
Forgetting capacitor ESR in high-frequency applications
Equivalent Series Resistance (ESR) causes energy loss and heating. For switching power supplies and RF circuits, low-ESR or ceramic capacitors are required — electrolytic capacitors have too high ESR at high frequencies.
Using wrong capacitor type for the application
Electrolytic: large values, low-frequency power filtering. Ceramic: small values, high-frequency decoupling. Film: precision timing and audio. Tantalum: stable, compact, but sensitive to overvoltage. Each type has specific use cases.
Quick Reference Table
| From | To |
|---|---|
| 1 F (farad) | 1,000,000 μF |
| 1 μF | 1,000 nF |
| 1 nF | 1,000 pF |
| 1 mF | 1,000 μF |
| Supercapacitor | 1 F to 3,000 F |
| Typical electrolytic | 1 μF to 10,000 μF |
| Typical ceramic (decoupling) | 100 nF = 0.1 μF |
| RF chip capacitor | 1-100 pF |
Frequently Asked Questions
Why is 1 farad such a large unit?
A 1 F capacitor stores 1 coulomb at 1 volt — that's 6.24 × 10¹⁸ electrons. The capacitance of a small sphere with 1 meter radius in vacuum is about 111 pF. Early capacitors were tiny; the farad was defined theoretically and practical values are much smaller. Modern supercapacitors achieving hundreds of farads use special nanomaterial electrodes.
How do I calculate RC time constant?
τ (tau) = R × C. One time constant is the time for a capacitor to charge to 63.2% or discharge to 36.8% of its initial value. Five time constants (5τ) = effectively fully charged/discharged. Example: 10 kΩ × 100 μF = 1 second. Very useful for delay circuits, filters, and oscillators.
What is the difference between a capacitor and a supercapacitor?
Conventional capacitors store energy in an electric field between two plates — very fast charge/discharge but small capacity. Supercapacitors (electrochemical double-layer capacitors) use ionic movement at electrode surfaces, achieving much higher capacitance (1-3,000 F) but lower voltage ratings (2.5-3 V per cell). They bridge the gap between batteries and capacitors.
Can capacitors be dangerous?
Yes. Large electrolytic capacitors in power supplies store significant energy (E = ½CV²). A 10,000 μF capacitor charged to 400 V stores 800 J — enough to cause severe burns or cardiac arrest. High-voltage capacitors in CRT TVs, microwave ovens, and industrial equipment retain their charge long after power is removed.
Why are decoupling capacitors placed close to IC power pins?
Decoupling capacitors act as local charge reservoirs for integrated circuits, supplying fast transient current before the wider power rail can respond. Placing them physically close to the power pins minimizes loop inductance and keeps the high-frequency impedance low. A common practice is to pair a 100 nF ceramic capacitor for fast switching noise with a larger bulk capacitor (for example 1-10 μF) nearby for lower-frequency transients.
Sources & Standards
- International Electrotechnical Commission (IEC)
- Institute of Electrical and Electronics Engineers (IEEE)
- National Institute of Standards and Technology (NIST)
- Horowitz, P. & Hill, W. — The Art of Electronics, 3rd ed. (Cambridge University Press)
Reviewed by The Unit Hub Editorial Team · March 2026