Staring at a tiny yellow cap marked 104 and wondering if that is 100 nF or 100 µF? Type the marking or a value like 100nF above and copy the readout. For resistor color bands, use the resistor color code calculator. This capacitor code calculator is part of the hardware tools on TechOpt.io.
How this capacitor code calculator reads ceramic EIA codes
Multilayer ceramic capacitors (MLCCs) and many SMD chips use a digit code printed on the body, described under ceramic capacitor value marking. The digits are always in picofarads (pF), but the multiplier digit makes the number readable:
- 2-digit: the value in pF.
22is 22 pF. - 3-digit: first two digits are significant figures; the third is the power of ten.
104is 10 × 10⁴ pF = 100,000 pF = 100 nF. - 4-digit: first three digits are significant figures; the fourth is the power of ten.
1002is 100 × 10² pF = 10,000 pF = 10 nF.
Electrolytic and tantalum caps usually print the value in plain text (100µF 16V) rather than a digit code. Film capacitors sometimes use color bands (similar to resistors), which this calculator does not cover.
Tolerance letters
| Letter | Tolerance |
|---|---|
| B | ±0.1% |
| C | ±0.25% |
| D | ±0.5% |
| F | ±1% |
| G | ±2% |
| J | ±5% |
| K | ±10% |
| M | ±20% |
| Z | +80/−20% |
FAQ
What does 104 mean on a capacitor?
On a ceramic or SMD cap, 104 is a 3-digit EIA code: 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 µF. It is a common decoupling value on PCBs. Do not read it as “104 picofarads” or “104 microfarads.”
What is the difference between 103 and 104?
103 is 10 × 10³ pF = 10,000 pF = 10 nF. 104 is 10 × 10⁴ pF = 100,000 pF = 100 nF — ten times larger. The last digit is the exponent, not part of the value itself.
Is 100 nF the same as 0.1 µF?
Yes. 100 nF = 0.1 µF = 100,000 pF. Schematics and BOMs mix nF and µF; this calculator shows all three so you can match the label on the part or the value in the schematic.
What does the letter after the code mean?
Letters like J, K, and M are tolerance codes. 104K is 100 nF ±10%. 104J is ±5%. The letter is not part of the capacitance calculation — it only tells you how far the actual value may drift from nominal.
When is a 4-digit code used instead of 3-digit?
4-digit codes (e.g. 1002 = 10 nF) give an extra significant figure for tighter-tolerance parts. Low-value caps under 100 pF often use a plain 2-digit code (22 = 22 pF) because no multiplier digit is needed.
Does this capacitor calculator upload my values?
No. It runs entirely in your browser. Markings and capacitance values never leave your machine.
Looking for more calculators? Decode resistor bands with the resistor color code calculator, size an LED with the LED resistor calculator, or browse the rest of the tools.