Capacitor Code Calculator
Enter the 3-digit or 4-digit code found on a ceramic or film capacitor to determine its capacitance value.
Result will appear here
Enter a code to calculate
Series & Parallel Capacitor Calculator
Enter capacitance values to find the total capacitance when connected in series or parallel. Use comma-separated values (e.g., 10, 22, 47).
Total in Series (Ceq)
Total in Parallel (Ceq)
RC Time Constant (τ) Calculator
Calculate the time constant of a resistor-capacitor circuit. This value represents the time it takes for the capacitor to charge to approximately 63.2% of the applied voltage.
Time Constant (τ)
Capacitive Reactance (Xc) Calculator
Calculate a capacitor's opposition to alternating current (AC) at a given frequency.
Capacitive Reactance (Xc)
How to Read Capacitor Codes
Ceramic, mylar, and other film capacitors often use a 3-digit or 4-digit numeric code. Here's how to interpret it:
- First two digits: These are the first two significant figures of the capacitance value.
- Third digit: This is the multiplier, representing the number of zeros to add to the first two digits. The value is in picofarads (pF).
- Example (104): The '10' are the significant figures. The '4' means add four zeros. So, 100,000 pF.
- "R" for decimal: If an "R" is present, it indicates a decimal point. For example, '2R2' means 2.2 pF.
Unit Conversions
| Unit | Symbol | Equivalent in Picofarads (pF) |
|---|---|---|
| Picofarad | pF | 1 pF |
| Nanofarad | nF | 1,000 pF |
| Microfarad | µF | 1,000,000 pF |
| Farad | F | 1,000,000,000,000 pF |
Frequently Asked Questions
What is a capacitor?
▼A capacitor is a passive electronic component that stores electrical energy in an electric field. It consists of two conductive plates separated by a dielectric (insulating) material.
What are the formulas for series and parallel capacitors?
▼Parallel: Ceq = C1 + C2 + ... + Cn
Series: 1/Ceq = 1/C1 + 1/C2 + ... + 1/Cn
What does the letter on a capacitor mean?
▼The letter often represents the capacitor's tolerance, which is the percentage variation from its nominal value. Common codes include: J (±5%), K (±10%), and M (±20%).
Design Verification Notes for Capacitor Calculator
These additions address practical search intent while preserving the original page structure and existing ranking content.
- Confirm the input units, tolerance range, and operating frequency before using the calculated value in a PCB design.
- Cross-check critical results with a datasheet formula, SPICE model, or bench measurement because ideal calculators omit parasitic resistance, capacitance, and inductance.
- When the result affects RF, timing, power, or filter behavior, reserve margin for component tolerance, temperature drift, and PCB layout parasitics.







