Electrical reference chart
Capacitor Code Chart
Use this capacitor code chart after the calculator result to document the marking, converted capacitance, tolerance, voltage rating, polarity, and circuit use.
Quick reference table
Use the chart to check common markings before opening the calculator: 104K = 100 nF at +/-10%, 223 = 22 nF, 475 = 4.7 uF, and 4R7 = 4.7 pF. Then confirm voltage rating, tolerance mark, polarity, dielectric type, package, and circuit role before using the value for timing, filtering, coupling, or replacement.
Common capacitor code conversions
| Code | pF | nF | uF |
|---|---|---|---|
| 101 | 100 pF | 0.1 nF | 0.0001 uF |
| 102 | 1,000 pF | 1 nF | 0.001 uF |
| 223 | 22,000 pF | 22 nF | 0.022 uF |
| 472 | 4,700 pF | 4.7 nF | 0.0047 uF |
| 103 | 10,000 pF | 10 nF | 0.01 uF |
| 104K | 100,000 pF | 100 nF | 0.1 uF at +/-10% |
| 105 | 1,000,000 pF | 1,000 nF | 1 uF |
| 475 | 4,700,000 pF | 4,700 nF | 4.7 uF |
| 4R7 | 4.7 pF | 0.0047 nF | 0.0000047 uF |
Replacement notes after decoding
| Marking or feature | What it affects | What to document |
|---|---|---|
| Voltage rating | Maximum applied voltage | Replacement rating must be suitable for the circuit |
| Polarity mark | Installation direction for polarized parts | Negative stripe or positive lead orientation |
| Tolerance letter | Allowed capacitance range | Timing or filter sensitivity |
| Dielectric type | Stability, loss, and temperature behavior | Use datasheet when circuit function depends on it |
Calculator handoff after decoding the marking
| Search intent | Open the calculator when | Keep with the result |
|---|---|---|
| Three-digit marking lookup | The code must be converted into pF, nF, and uF without losing the original marking | Visible code, letter suffix, converted value, and uncertainty if the marking is damaged |
| Replacement screening | The decoded value must be checked with voltage rating, polarity, tolerance, and package constraints | Voltage mark, polarity mark, dielectric family, tolerance letter, and package note |
| Timing or filter work | The decoded capacitance feeds RC timing, reactance, series, or parallel capacitor math | Circuit role, resistance or frequency context, and tolerance band |
| Unknown or manufacturer-specific marking | The code is incomplete, mixed with a series code, or needs a datasheet before reuse | Photo/marking note, manufacturer family, datasheet source, and do-not-substitute flag |
How to use this chart
Read the value code
Identify the three-digit capacitance code before converting it into pF, nF, or uF.
Check extra markings
Look for voltage rating, polarity, tolerance letters, or manufacturer marks before treating the decoded value as enough information.
Connect the value to use
After the calculator result, note whether the capacitor is used for timing, filtering, coupling, bypass, or replacement.
Worksheet checklist
- Record the markingWrite the visible code, any letter suffix, voltage marking, and polarity mark before selecting a replacement or calculator path.
- Convert all unitsDocument the value in pF, nF, and uF so it can be reused in timing and reactance calculators without unit confusion.
- Add circuit constraintsRecord voltage, polarity, dielectric, tolerance, and physical package notes when the value affects a real circuit decision.
Common mistakes to avoid
- Reading 104 as 104 pF instead of 100,000 pF, 100 nF, or 0.1 uF.
- Ignoring polarity or voltage rating when replacing an electrolytic or other marked capacitor.
- Using the decoded capacitance in timing or reactance work without accounting for tolerance and dielectric behavior.
Formula basis
Three-digit code value in pF = first two digits x 10^(third digit). Convert pF to nF by dividing by 1,000 and to uF by dividing by 1,000,000.
- The first two digits are significant figures.
- The third digit is the power-of-ten multiplier in picofarads.
- Converted capacitance can be expressed in pF, nF, or uF.
- Letter markings may indicate tolerance, and R-coded markings use R as the decimal point in picofarads.
Worked examples
Decode code 104 for a bypass capacitor
Code 104K means 10 x 10^4 pF = 100,000 pF, which is 100 nF or 0.1 uF, with K commonly read as +/-10% tolerance. The next check is the voltage rating and whether the dielectric is suitable for the circuit location.
Decode code 472 for a timing circuit
Code 472 means 47 x 10^2 pF = 4,700 pF, which is 4.7 nF or 0.0047 uF. In an RC timing circuit, tolerance can move the timing result enough to matter.
Assumptions
- The chart covers common three-digit capacitor value markings used on many small capacitors.
- Voltage rating, dielectric type, polarity, tolerance, package, and manufacturer markings still need separate verification.
- A decoded value does not approve a substitution in a power supply, motor, safety, or manufacturer-controlled assembly.
Code and standard notes
- This chart identifies component value and does not approve capacitor substitution, stored-energy handling, or equipment repair decisions by itself.
Related calculators
Related charts
Capacitor Reactance Chart
Use this capacitor reactance chart: 10 uF at 60 Hz is about 265 ohms; 120 V across it estimates 0.45 A before ESR and ratings.
RC Time Constant Chart
Use this RC time constant chart: tau = R x C, 10 kOhm x 47 uF = 0.47 s, and 5 tau = 2.35 s for charge, discharge, or debounce checks.
Frequently asked questions
These answers explain how to use the chart without turning a quick reference into a final design decision.