When you read a 3-digit code like '104' on a ceramic capacitor, it translates to 100,000 pF, which is exactly 100 nF or 0.1 µF. This capacitor conversion table maps standard EIA 3-digit codes to metric units (pF, nF, µF) and factors in critical dielectric derating metrics. Bookmark this reference for your bench to eliminate unit-conversion guesswork and avoid the most common PCB design trap: assuming a capacitor's printed value equals its effective value under load.

The Master Capacitor Conversion & EIA Code Table

How to read this table: The 3-digit code follows the IEC 60062 standard. The first two digits are the significant figures, and the third digit is the multiplier (number of zeros to add), yielding a base value in picofarads (pF). To convert to nanofarads (nF), divide the pF value by 1,000. To convert to microfarads (µF), divide the pF value by 1,000,000. The final column lists the typical dielectric material, which dictates the component's thermal and voltage stability.

3-Digit Code Multiplier Picofarads (pF) Nanofarads (nF) Microfarads (µF) Typical Dielectric
100 ×1 10 pF 0.01 nF 0.00001 µF C0G / NP0
101 ×10 100 pF 0.1 nF 0.0001 µF C0G / NP0
102 ×100 1,000 pF 1 nF 0.001 µF C0G / X7R
103 ×1,000 10,000 pF 10 nF 0.01 µF X7R / X7S
104 ×10,000 100,000 pF 100 nF 0.1 µF X7R / Y5V
105 ×100,000 1,000,000 pF 1,000 nF 1.0 µF X5R / X7R
222 ×100 2,200 pF 2.2 nF 0.0022 µF C0G / X7R
223 ×1,000 22,000 pF 22 nF 0.022 µF X7R
224 ×10,000 220,000 pF 220 nF 0.22 µF X7R / X5R
472 ×100 4,700 pF 4.7 nF 0.0047 µF C0G / X7R
473 ×1,000 47,000 pF 47 nF 0.047 µF X7R
474 ×10,000 470,000 pF 470 nF 0.47 µF X7R / X5R

Which column applies to your installation? The Typical Dielectric column is the most critical for installation suitability. If you are building a high-temperature automotive sensor or a precision RF oscillator, you must select a C0G/NP0 dielectric. If you are placing general-purpose decoupling caps on an ESP32 VCC rail, X7R is your standard. Never install Y5V in a circuit that experiences wide temperature swings, as its capacitance can drop by 80% just from reaching 85°C.

Decoding Derating: Why Your 10µF Cap is Only 2µF

The most dangerous assumption in electronics is that a capacitor's printed value is its actual value in-circuit. For Multi-Layer Ceramic Capacitors (MLCCs), the dielectric material heavily influences how voltage and temperature modify the base value. Class II dielectrics (like X7R and X5R) rely on barium titanate (BaTiO₃) crystals. When a DC voltage is applied, the crystal lattice aligns with the electric field, drastically reducing the dielectric constant (k) and, consequently, the capacitance.

Notice how the DC Bias Derating row in the comparison below modifies the base value: a 10µF X5R capacitor in a tiny 0805 footprint might only deliver 1.5µF of actual capacitance when biased at its rated 6.3V.

EIA Temp Code Class Base Capacitance Stability DC Bias Derating (at 50% Vr) Temp Derating (+85°C)
C0G / NP0 Class I Ultra-Stable (±30ppm/°C) 0% loss Negligible
X7R Class II Moderate (±15%) -20% to -40% loss -15% loss
X5R Class II Moderate (±15%) -30% to -60% loss -15% loss
Y5V Class II Poor (+22% / -82%) -50% to -80% loss -60%+ loss
Bench Rule of Thumb for MLCC Derating: To mitigate DC bias derating in power supply filtering, always select a capacitor with a voltage rating at least double your maximum rail voltage. If you are filtering a 5V rail, use a 10V or 16V rated X5R/X7R capacitor. Alternatively, step up the physical footprint size (e.g., use a 1206 case instead of an 0805); larger physical volumes of barium titanate resist DC bias saturation much better than smaller ones. For exact curves, consult manufacturer tools like Murata's SimSurfing or KEMET's KSIM before finalizing your BOM.

What the Table Cannot Tell You (Bench & Layout Realities)

While a capacitor conversion table perfectly solves unit math and EIA code translation, it is blind to the parasitic realities of physical components. When moving from schematic to PCB layout or breadboard prototyping, you must account for the following missing variables:

  • Equivalent Series Resistance (ESR): The table assumes an ideal capacitor. In reality, every cap has internal resistance. In switching power supplies (like a buck converter feeding an Arduino), high ESR causes massive heat generation and output voltage ripple. Always check the datasheet for ESR (measured in milliohms) when placing caps on the output of voltage regulators.
  • Equivalent Series Inductance (ESL): The physical loop size of the capacitor and its PCB traces creates inductance. This is why a 100nF (104) cap in a massive through-hole package will fail to bypass high-frequency noise on an ESP32's 3.3V rail compared to a tiny 0402 SMD 104 cap placed directly adjacent to the VCC pin. Smaller physical size equals lower ESL and higher effective resonant frequency.
  • Lead Spacing (Pitch): For through-hole ceramic or electrolytic capacitors, the conversion table won't tell you if the part fits your board. Standard radial ceramic disc pitches are typically 2.5mm, 5.0mm, or 7.5mm. Always verify the 'P' (pitch) dimension in the mechanical drawing before ordering.
  • Ripple Current Rating: Crucial for aluminum electrolytic capacitors used in bulk filtering. If the AC ripple current exceeds the capacitor's thermal limit, the internal electrolyte will boil, vent, and eventually short or open. The capacitance value is irrelevant if the component destroys itself from internal I²R heating.

Keep this conversion chart pinned above your workbench for instant EIA code translation, but always pair it with a deep dive into the manufacturer's datasheet for DC bias, ESR, and thermal limits before committing to a production design.