Capacitor Code Decoder

Decode common capacitor markings (like 104, 473) into pF / nF / µF. Add tolerance/voltage markings if you have them.

How to Use

  1. Enter a code like 104 (3-digit pF code).
  2. Optionally enter a tolerance letter (like K, J).
  3. Optionally enter a voltage marking (if printed on your capacitor).
  4. Results update instantly, and “Show Work” explains the math.
Decoder Readout
Auto-scales value and shows the base pF math.
Value
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pF
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Tol
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Volt
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Decode: —
Quick Reference

3-digit code: first two digits are significant, third digit is the number of zeros in pF. Example: 104 → 10 + 4 zeros = 100000 pF = 100 nF = 0.1 µF.

Inputs
Supports typical ceramic/film 3-digit markings plus optional tolerance/voltage notes.
Try: 104, 472, 331. Some parts print “0.1uF” instead of a 3-digit code.
Common letters: J (±5%), K (±10%), M (±20%).
If your part prints something like “50V” enter it as-is. Some SMD voltage codes vary by series.
Auto chooses the most readable unit; override if you want fixed outputs.
Show Work (step-by-step)
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Work is shown using base capacitance units (pF) first, then scaled to nF/µF.

Reference

  • 3-digit code: XY Z means XY × 10^Z pF
  • Examples: 104 = 100,000 pF = 100 nF = 0.1 µF • 472 = 4,700 pF = 4.7 nF
  • Tolerance letters: often printed as a single letter near the value (varies by series)
  • Voltage markings: sometimes explicit (e.g., 50V) and sometimes series-coded

FAQ

What does “104” mean on a capacitor?

It’s a 3-digit pF code: 10 × 10^4 pF = 100000 pF = 100 nF = 0.1 µF.

Why do some capacitors show “0.1uF” instead of a code?

Some parts print the value directly. This tool supports both direct values and 3-digit codes (unless Strict mode is enabled).

Can this decode every SMD voltage code?

Not reliably without knowing the capacitor series/manufacturer. This tool treats voltage markings as “best effort” unless the marking is an explicit voltage like 50V.

Is capacitance the only important spec?

No—voltage rating, dielectric type, tolerance, ESR, and temperature coefficient matter too (especially for power and timing circuits).

Tool Info

Last updated:

Updates may include additional tolerance/voltage mappings and more marking patterns.