A capacitor code calculator decodes the 3-digit markings printed on ceramic disc and multilayer capacitors to reveal the actual capacitance in picofarads, nanofarads, and microfarads. Whether you are building a filter circuit or sorting through a parts bin, this tool saves you from memorizing the code chart.
Mode
Enter the 3-digit code (e.g., 104) or R-notation (e.g., 1R5)
Result
Tolerance & Voltage Code Reference
Tolerance Codes
| Letter | Tolerance |
|---|
Voltage Rating Codes
| Letter | Voltage |
|---|
Common Capacitor Values
| Code | pF | nF | µF | Common Use |
|---|
How to Use the Capacitor Code Calculator
Ceramic disc and multilayer capacitors use a compact 3-digit code printed on their body to indicate capacitance. Reading these markings by hand requires either a reference chart or a good memory. This capacitor code calculator handles the conversion instantly so you can focus on your circuit design.
Step 1: Enter the Code or Value
In Decode mode, type the 3-digit code printed on the capacitor into the input field. For example, enter 104 to decode a common 100 nF capacitor. The tool also supports R-notation for sub-10 pF values, such as 1R5 for 1.5 pF. Switch to Reverse Lookup mode when you know the capacitance value and need the printed code.
Step 2: Understand the 3-Digit System
The first two digits are the significant figures and the third digit tells you how many zeros to append. The result is always in picofarads. So 473 means 47 followed by three zeros, giving 47,000 pF, which is 47 nF. A third digit of 0 means no zeros are added: 220 equals exactly 22 pF.
Step 3: Read the Result
The calculator displays the capacitance in all three common units: picofarads (pF), nanofarads (nF), and microfarads (uF). It also shows the 3-digit code, a human-readable breakdown of how the code is interpreted, and the tolerance if a tolerance letter is selected. The capacitor diagram updates to show the code visually on a ceramic disc.
Step 4: Use Tolerance and Voltage Codes
Capacitors often include additional letters after the 3-digit code. The tolerance letter tells you how close the actual capacitance is to the marked value: J means plus or minus 5 percent, K is 10 percent, and M is 20 percent. Voltage codes like H (50V) or E (25V) indicate the maximum working voltage. Open the reference tables below the calculator for the complete list of codes.
Common Capacitor Values
The most frequently encountered ceramic capacitors in hobby electronics are 100 nF (code 104), used for decoupling; 10 nF (code 103), common in filters; and 22 pF (code 220), often paired with crystal oscillators. The common values table in this tool lists popular codes with their typical applications, making it easy to identify unlabeled components in your parts bin.
FAQ
Is this capacitor code calculator free?
Yes, the capacitor code calculator is completely free with no limits. Decode as many capacitor codes as you need without creating an account or paying anything.
Is my data safe when using this tool?
Absolutely. All calculations run entirely in your browser using JavaScript. No data is ever sent to any server. The tool works completely offline once the page loads.
What does the 3-digit code on a capacitor mean?
The first two digits are the significant figures and the third digit is the number of zeros to add, giving the value in picofarads. For example, 104 means 10 followed by four zeros, which is 100,000 pF or 100 nF.
What does the R in a capacitor code like 1R5 mean?
The letter R acts as a decimal point. So 1R5 means 1.5 pF. This notation is used for very small capacitance values below 10 pF where the standard 3-digit code cannot represent the value.
How do I convert between pF, nF, and uF?
Divide by 1,000 to go from pF to nF, and divide by 1,000 again to go from nF to uF. For example, 100,000 pF equals 100 nF equals 0.1 uF. This calculator shows all three units automatically.
What do the tolerance letters on capacitors mean?
Letters printed after the code indicate manufacturing tolerance. Common ones are J for plus or minus 5%, K for plus or minus 10%, and M for plus or minus 20%. Tighter tolerances like F (1%) and G (2%) are used in precision circuits.
What voltage rating letters appear on ceramic capacitors?
Voltage ratings may use letter codes: J is 6.3V, A is 10V, C is 16V, D is 20V, E is 25V, V is 35V, and H is 50V. Always verify the voltage rating matches your circuit requirements to avoid capacitor failure.
Can I look up the 3-digit code from a capacitance value?
Yes. Switch to Reverse Lookup mode, enter your desired capacitance value, and select the unit. The calculator will display the standard 3-digit code that represents that value, making it easy to find the right capacitor.