SMD and capacitor marking calculator
«473» on a resistor means 47 kilohms; on a capacitor it means 47 nanofarads. There is no other clue than the package and the place in the circuit. Add four different resistor marking schemes on top of that, and reading those three characters turns out to be a skill of its own.
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💡 Capacitor tolerance lettersB — ±0.1 pF · C — ±0.25 pF · D — ±0.5 pF · F — ±1 % · G — ±2 % · J — ±5 % · K — ±10 % · M — ±20 % · Z — +80 / −20 % The same code «473» means 47 kΩ on a resistor and 47 nF on a capacitor. You have to tell them apart by the package and by the place in the circuit; there is no other clue. | |||||||||||||||||||
📐 Marking schemes
| Notation | What it means | Example |
|---|---|---|
| 3 digits | two digits + the number of zeros | 473 = 47 kΩ |
| 4 digits | three digits + the number of zeros | 4702 = 47 kΩ |
| R notation | R in place of the decimal point | R47 = 0.47 Ω, 4R7 = 4.7 Ω |
| EIA-96 | two digits of the E96 code + a multiplier letter | 01C = 10 kΩ |
| Capacitor | three digits in picofarads | 104 = 100 nF |
EIA-96 multipliers:
Z = 0.001 Y or R = 0.01 X or S = 0.1 A = 1
B or H = 10 C = 100 D = 1000 E = 10 000 F = 100 000
Capacitor tolerance letters:
J = ±5 % K = ±10 % M = ±20 % F = ±1 % G = ±2 %
- The same code reads differently on a resistor and on a capacitor — the calculator shows both readings
- EIA-96 is used on small packages (0402, 0603), where three digits do not fit
- Some manufacturers have their own marking that fits none of these schemes
- Large-value capacitors are often marked straight in microfarads, with no code
🎯 Where it is used
- Repairing a board: what this resistor is and what to replace it with.
- Reading someone else's circuit from a photograph of the board.
- Finding the value behind a code when you have to order a replacement.
- Packages of 0402 and smaller are almost always marked to EIA-96, or not marked at all.
- Capacitors on a board most often carry no marking whatsoever — there only the schematic helps.
- «000» or «0» means a zero-ohm link, not zero picofarads.
- Check what you have read with a multimeter: a value that does not fit E24 is a reason to doubt it.
© 2026 UR3PKI · CyberDev.Space · Content licensed under CC BY-NC-SA 4.0.
How to cite this calculator
UR3PKI. «SMD and capacitor marking calculator». CyberDev.Space. https://cyberdev.space/en/radio/calculators/coils/smd_code (licence CC BY-NC-SA 4.0).The licence lets you use this material freely, including in teaching materials, but only with attribution to the author and a link to the source.