The direct answer for the most common bench conversions: 1 microfarad (µF) equals 1,000 nanofarads (nF) and 1,000,000 picofarads (pF). If you are reading a schematic calling for a 100nF decoupling capacitor, you need a 0.1µF part. If your code or BOM specifies 10,000pF, you are looking for a 10nF or 0.01µF capacitor.
However, a bare unit conversion is only half the battle. In wire sizing, you must consult temperature and bundling columns to find true ampacity. In capacitor selection, you must consult EIA temperature characteristic codes and DC bias derating curves to find true capacitance. A 10µF ceramic capacitor biased near its rated voltage can physically drop to 2µF on your board. Below is the complete reference chart, followed by the decision framework to ensure the part you buy actually behaves like the part you designed.
The Core Capacitance Conversion Table
The following table maps the standard IEC 60384 and EIA RS-198 capacitance values across picofarads, nanofarads, microfarads, and millifarads. It also includes the typical EIA Class I/II temperature code associated with that value range in modern surface-mount ceramics.
| Picofarads (pF) | Nanofarads (nF) | Microfarads (µF) | Millifarads (mF) | Typical EIA Temp Code | Common Application |
|---|---|---|---|---|---|
| 10 pF | 0.01 nF | 0.00001 µF | - | C0G / NP0 | RF tuning, high-Q filters |
| 100 pF | 0.1 nF | 0.0001 µF | - | C0G / NP0 | Snubbers, RF bypass |
| 1,000 pF (1k) | 1 nF | 0.001 µF | - | C0G / X7R | Audio coupling, EMI filtering |
| 10,000 pF (10k) | 10 nF | 0.01 µF | - | X7R | Mid-frequency decoupling |
| 100,000 pF (100k) | 100 nF | 0.1 µF | - | X7R | Standard digital IC bypass |
| 1,000,000 pF (1M) | 1,000 nF | 1 µF | 0.001 mF | X7R / X5R | Local power rail decoupling |
| 10,000,000 pF (10M) | 10,000 nF | 10 µF | 0.01 mF | X5R | Bulk ceramic storage |
| 100,000,000 pF (100M) | 100,000 nF | 100 µF | 0.1 mF | X5R / Y5V | Low-freq bulk, LDO input |
| 1,000,000,000 pF (1G) | 1,000,000 nF | 1,000 µF | 1 mF | Electrolytic / Polymer | Power supply reservoir |
How to Read the Table: Temperature Columns & EIA Codes
When sizing THHN wire, you look at the 60°C, 75°C, or 90°C column to determine ampacity based on your termination ratings. When sizing ceramic capacitors, your equivalent 'temperature column' is the EIA Dielectric Code (defined in EIA RS-198). This code tells you exactly how much capacitance you will lose as the board temperature changes.
- C0G (NP0): Class I dielectric. Temperature coefficient is 0 ±30ppm/°C. It does not drift with temperature or applied voltage. Use this for precision analog, RF, and filter networks.
- X7R: Class II dielectric. Rated from -55°C to +125°C with a maximum capacitance change of ±15%. This is the workhorse for general digital decoupling.
- X5R: Class II dielectric. Rated from -55°C to +85°C with a maximum change of ±15%. Used for higher capacitance values (10µF and up) where X7R chemistry becomes physically too large or expensive.
- Y5V: Class III dielectric. Rated -30°C to +85°C, but can lose up to 82% of its capacitance at temperature extremes. Avoid this unless you are designing ultra-low-cost consumer toys.
Which column applies to your installation? If your PCB operates in an unconditioned environment (like an automotive dashboard or outdoor IoT sensor) where ambient temperatures exceed 85°C, the X5R column is invalid. You must specify X7R or C0G, or your 10µF bulk capacitor will drop out of regulation when the summer sun hits the enclosure.
DC Bias Derating: How Real-World Voltage Modifies Base Values
The conversion table above assumes 0V DC bias. In reality, Class II ceramic capacitors (X7R, X5R) suffer from severe DC bias derating. The ferroelectric barium titanate dielectric loses its permittivity as the DC electric field increases. According to Murata's technical documentation on DC bias characteristics, a standard 10µF, 0805-package, 25V X5R capacitor might only provide 2.0µF of actual capacitance when biased at 20V DC.
How derating modifies the base value: If your circuit requires a strict 10µF minimum to maintain loop stability on a buck converter operating at 12V DC, buying a 10µF/16V X5R capacitor will result in catastrophic failure. At 12V bias, that 16V part is derated by roughly 60%, leaving you with only 4µF.
Decision Tree: Selecting the Right Dielectric and Package
Use this decision path to terminate your selection process with a concrete part number. This assumes standard 2-layer or 4-layer FR4 PCBs operating at room temperature.
| Condition / Requirement | Dielectric Pick | Concrete Default Part (0805 Package) |
|---|---|---|
| IF signal path is RF/analog (<100kHz) AND requires high Q / low distortion | C0G / NP0 | KEMET C0805C100J5GACTU (10pF 50V C0G) |
| IF digital IC decoupling (100kHz to 50MHz) AND standard temp range | X7R | KEMET C0805C104K5RACTU (100nF 50V X7R) |
| IF bulk local storage (>1µF) AND DC bias is <50% of rated voltage | X5R | Murata GRM21BR61E106KA73 (10µF 25V X5R) |
| IF audio signal coupling AND must avoid piezoelectric microphonics | Film / C0G | WIMA MKS2 (Through-hole PET Film) or large C0G |
The 'Desert Island' Default Pick: If you are stocking a lab or building a generic ESP32/Arduino breakout board and need one bulk and one bypass part, buy the KEMET C0805C104K5RACTU (0.1µF X7R 50V) for every VCC pin, and the Murata GRM21BR61E106KA73 (10µF X5R 25V) for the main 3.3V/5V rail entry. These two part numbers cover 95% of hobbyist and commercial low-power digital designs.
What This Table Cannot Tell You
A capacitance conversion chart only solves the static, low-frequency, zero-bias value. It completely omits three critical parameters that dictate high-frequency and power-supply performance:
- ESR (Equivalent Series Resistance): A 100µF electrolytic and a 100µF polymer capacitor have the same base capacitance, but the polymer's ESR might be 5mΩ while the electrolytic is 500mΩ. In a switching regulator, high ESR causes massive output voltage ripple and internal capacitor heating. As noted in All About Circuits' capacitor theory guide, ESR is often the limiting factor in power supply lifespan.
- ESL (Equivalent Series Inductance): Every capacitor is an inductor at high frequencies. A 100nF 0805 capacitor will self-resonate around 40MHz. Above that frequency, it acts as an inductor and provides zero decoupling. This is why you place a 10nF (smaller physical package, lower ESL) in parallel with a 100nF to suppress high-frequency GHz ringing.
- Piezoelectric Microphonics: Class II ceramics (X7R, X5R) are physically piezoelectric. Mechanical vibration on the PCB will generate voltage noise on the power rail, and AC ripple on the rail will cause the capacitor to physically vibrate, acting as a tiny speaker (coil whine). If you are designing an audio preamp or a high-gain sensor front-end, never use X7R/X5R in the signal path; use C0G or film capacitors.
Mastering the conversion from picofarads to microfarads gets you the right number on the BOM. Understanding temperature drift, DC bias derating, and parasitic ESL ensures that number actually functions in the physical world.
