IEC 60063 · E12 · E24 · E48 · E96 · E192
Enter the value you calculated: the closest standard resistor in every E-series, or a series or parallel pair that gets even closer, with its colour code.
Accepted: 4700 · 4.7k · 4k7 · 0R47 · 2.2M · 150m (milliohms)
Closest single value and best two-resistor pairs in each series, with the relative error to your target.
| Series | Single | Error | Series R1 + R2 | Error | Parallel R1 ∥ R2 | Error |
|---|
Highlighted cells: overall best match. Disabled combinations show “—”. Negative error = below target.
The E-series defined by IEC 60063 are preferred numbers spaced geometrically within each decade. E12 has 12 values (±10 %), E24 has 24 (±5 %), E48 has 48 (±2 %), E96 has 96 (±1 %) and E192 has 192 (±0.5 % and better). E12 and E24 use two significant digits, the others three.
Combine two standard resistors. In series R = R1 + R2; in parallel R = R1·R2 / (R1 + R2). A pair from E12 or E24 often gets closer than a single precision part, and the combination keeps the tolerance of its parts.
For each enabled series it lists the standard values over several decades around your target and keeps the closest one by relative error. With combinations enabled, it takes every standard value as R1 and looks for the best partner R2 (series: R2 = target − R1; parallel: 1/R2 = 1/target − 1/R1). The overall winner has the lowest absolute error; on a tie, a single part beats a pair, then the more common series wins. E192 and the combinations are off by default: enable them for tighter results.
E12 and E24 parts use 4 bands: two digits, a multiplier and the tolerance. From E48 upward, 5 bands are used: three digits, a multiplier and the tolerance (red ±2 %, brown ±1 %, green ±0.5 %).