Standard Resistor Values — E-Series Table
Full IEC 60063 reference tables for E3–E192 preferred values, plus a finder that snaps any resistance to the nearest standard value.
E3, E6, E12 & E24 preferred values
One decade of each series — multiply by any power of ten (4.7 → 47 Ω, 470 Ω, 4.7 kΩ, 47 kΩ…). Each series is a subset of the one below it.
| E24 ±5% | E12 ±10% | E6 ±20% | E3 |
|---|---|---|---|
| 1.0 | 1.0 | 1.0 | 1.0 |
| 1.1 | |||
| 1.2 | 1.2 | ||
| 1.3 | |||
| 1.5 | 1.5 | 1.5 | |
| 1.6 | |||
| 1.8 | 1.8 | ||
| 2.0 | |||
| 2.2 | 2.2 | 2.2 | 2.2 |
| 2.4 | |||
| 2.7 | 2.7 | ||
| 3.0 | |||
| 3.3 | 3.3 | 3.3 | |
| 3.6 | |||
| 3.9 | 3.9 | ||
| 4.3 | |||
| 4.7 | 4.7 | 4.7 | 4.7 |
| 5.1 | |||
| 5.6 | 5.6 | ||
| 6.2 | |||
| 6.8 | 6.8 | 6.8 | |
| 7.5 | |||
| 8.2 | 8.2 | ||
| 9.1 |
E48 preferred values ±2%
| 1.00 | 1.05 | 1.10 | 1.15 | 1.21 | 1.27 | 1.33 | 1.40 |
| 1.47 | 1.54 | 1.62 | 1.69 | 1.78 | 1.87 | 1.96 | 2.05 |
| 2.15 | 2.26 | 2.37 | 2.49 | 2.61 | 2.74 | 2.87 | 3.01 |
| 3.16 | 3.32 | 3.48 | 3.65 | 3.83 | 4.02 | 4.22 | 4.42 |
| 4.64 | 4.87 | 5.11 | 5.36 | 5.62 | 5.90 | 6.19 | 6.49 |
| 6.81 | 7.15 | 7.50 | 7.87 | 8.25 | 8.66 | 9.09 | 9.53 |
E96 preferred values ±1%
| 1.00 | 1.02 | 1.05 | 1.07 | 1.10 | 1.13 | 1.15 | 1.18 |
| 1.21 | 1.24 | 1.27 | 1.30 | 1.33 | 1.37 | 1.40 | 1.43 |
| 1.47 | 1.50 | 1.54 | 1.58 | 1.62 | 1.65 | 1.69 | 1.74 |
| 1.78 | 1.82 | 1.87 | 1.91 | 1.96 | 2.00 | 2.05 | 2.10 |
| 2.15 | 2.21 | 2.26 | 2.32 | 2.37 | 2.43 | 2.49 | 2.55 |
| 2.61 | 2.67 | 2.74 | 2.80 | 2.87 | 2.94 | 3.01 | 3.09 |
| 3.16 | 3.24 | 3.32 | 3.40 | 3.48 | 3.57 | 3.65 | 3.74 |
| 3.83 | 3.92 | 4.02 | 4.12 | 4.22 | 4.32 | 4.42 | 4.53 |
| 4.64 | 4.75 | 4.87 | 4.99 | 5.11 | 5.23 | 5.36 | 5.49 |
| 5.62 | 5.76 | 5.90 | 6.04 | 6.19 | 6.34 | 6.49 | 6.65 |
| 6.81 | 6.98 | 7.15 | 7.32 | 7.50 | 7.68 | 7.87 | 8.06 |
| 8.25 | 8.45 | 8.66 | 8.87 | 9.09 | 9.31 | 9.53 | 9.76 |
E192 preferred values ±0.5%
| 1.00 | 1.01 | 1.02 | 1.04 | 1.05 | 1.06 | 1.07 | 1.09 |
| 1.10 | 1.11 | 1.13 | 1.14 | 1.15 | 1.17 | 1.18 | 1.20 |
| 1.21 | 1.23 | 1.24 | 1.26 | 1.27 | 1.29 | 1.30 | 1.32 |
| 1.33 | 1.35 | 1.37 | 1.38 | 1.40 | 1.42 | 1.43 | 1.45 |
| 1.47 | 1.49 | 1.50 | 1.52 | 1.54 | 1.56 | 1.58 | 1.60 |
| 1.62 | 1.64 | 1.65 | 1.67 | 1.69 | 1.72 | 1.74 | 1.76 |
| 1.78 | 1.80 | 1.82 | 1.84 | 1.87 | 1.89 | 1.91 | 1.93 |
| 1.96 | 1.98 | 2.00 | 2.03 | 2.05 | 2.08 | 2.10 | 2.13 |
| 2.15 | 2.18 | 2.21 | 2.23 | 2.26 | 2.29 | 2.32 | 2.34 |
| 2.37 | 2.40 | 2.43 | 2.46 | 2.49 | 2.52 | 2.55 | 2.58 |
| 2.61 | 2.64 | 2.67 | 2.71 | 2.74 | 2.77 | 2.80 | 2.84 |
| 2.87 | 2.91 | 2.94 | 2.98 | 3.01 | 3.05 | 3.09 | 3.12 |
| 3.16 | 3.20 | 3.24 | 3.28 | 3.32 | 3.36 | 3.40 | 3.44 |
| 3.48 | 3.52 | 3.57 | 3.61 | 3.65 | 3.70 | 3.74 | 3.79 |
| 3.83 | 3.88 | 3.92 | 3.97 | 4.02 | 4.07 | 4.12 | 4.17 |
| 4.22 | 4.27 | 4.32 | 4.37 | 4.42 | 4.48 | 4.53 | 4.59 |
| 4.64 | 4.70 | 4.75 | 4.81 | 4.87 | 4.93 | 4.99 | 5.05 |
| 5.11 | 5.17 | 5.23 | 5.30 | 5.36 | 5.42 | 5.49 | 5.56 |
| 5.62 | 5.69 | 5.76 | 5.83 | 5.90 | 5.97 | 6.04 | 6.12 |
| 6.19 | 6.26 | 6.34 | 6.42 | 6.49 | 6.57 | 6.65 | 6.73 |
| 6.81 | 6.90 | 6.98 | 7.06 | 7.15 | 7.23 | 7.32 | 7.41 |
| 7.50 | 7.59 | 7.68 | 7.77 | 7.87 | 7.96 | 8.06 | 8.16 |
| 8.25 | 8.35 | 8.45 | 8.56 | 8.66 | 8.76 | 8.87 | 8.98 |
| 9.09 | 9.20 | 9.31 | 9.42 | 9.53 | 9.65 | 9.76 | 9.88 |
How the E-series work
Component values follow geometric series defined in IEC 60063, spaced so that each value's tolerance band roughly meets the next one's — E12 parts at ±10% step every ~20%, E24 at ±5% every ~10%, and so on. That's why you can buy a 4.7 kΩ resistor everywhere but never a 5 kΩ one.
value(n) = 10^(n / N), n = 0 … N−1, rounded
E48, E96, and E192 follow that formula rounded to three significant figures, with a single quirk: the standard lists 9.20 in E192 where the formula (10^(185/192) ≈ 9.194) rounds to 9.19. E24 and below are older lists that deviate from the pure formula in several places (the formula would give 2.61 and 8.25 where E24 uses 2.7 and 8.2) — which is why a calculator must use the standardised tables, not the formula alone.
Using them
The same series apply to capacitors, inductors, and Zener voltages. If no single value is close enough, two standard parts inseries or parallelusually get you there; for ratio problems thepotential divider calculatorsearches E-series pairs directly. Decode a part you already have with theresistor color code calculator.
Common questions
- What is IEC 60063?
- It is the international standard that defines the preferred number series for resistors and capacitors — the reason a shop sells 4.7 kΩ and 10 kΩ but never 4.8 kΩ. The standard sets out the E3, E6, E12, E24, E48, E96 and E192 series, each named for how many values it contains per decade. It is the formal source behind what most people simply call "standard resistor values".
- Why are the values not round numbers?
- Because they are spaced by a constant ratio rather than a constant amount, so that the percentage gap between neighbours stays the same across the whole range. Each series divides a decade into equal logarithmic steps: E12 uses the 12th root of 10 (about 1.21, roughly 20% apart), E24 the 24th root. That way a 10% tolerance part in the E12 series covers the gap to the next value with neither a hole nor much overlap — which is exactly what the tolerance is for.
- Why does the standard list 2.7 when the formula gives 2.61?
- Because the lower series are historical lists, not generated ones. E3 through E24 were fixed by convention before the mathematics was tidied up, and several entries were rounded to friendlier numbers — 2.7 rather than 2.61, 8.2 rather than 8.25, 3.3 rather than 3.16. E48 and above follow the formula properly. This site's tables use the published lists rather than the formula, because those are the parts you can actually buy.
- Which series should I use?
- Match the series to the tolerance you are buying. E12 pairs with 10% parts, E24 with 5%, E96 with 1%. There is no point specifying an E96 value if you are fitting a 5% resistor, because the tolerance band is wider than the gap to the neighbouring value. In practice most modern surface-mount stock is 1% E96 and costs no more, so the older series matter mainly for through-hole parts and for reading existing designs.