# Inductor codes

Small inductors often use a numeric code to indicate the inductance. This code consists of thee numbers and sometimes an additional letter.

### Calculator

You can use this calculator to calculate the inductance and tolerance of an inductor.

### Calculation

The inductance in microhenry (μH) is equal to the first two digits multiplied by ten to the power of the third digit: C = AB·10 ^{C }. Some codes contain the letter R, which represents the decimal point. The inductance in μH is equal to all digits linked together with a decimal point on the location of the R in this case. The letter at the end indicates the tolerance. These values can be found in the table below.

letter | tolerance | letter | tolerance |
---|---|---|---|

A | 0.05nH | H | 3% |

B | 0.1nH | J | 5% |

C | 0.25nH | K | 10% |

D | 0.5nH | L | 15% |

E | 0.5% | M | 20% |

F | 1% | V | 25% |

G | 2% | N | 30% |

Z | +80% -20% | - | - |

### Example

We have an inductor with the code 332F. The inductance is 33·10 ^{2 }μH = 3.3mH. The tolerance for F = 1%.