Standard Resistor Value (E6 to E192 Series)

Your divider math says 4600 Ω, but nobody manufactures a 4600 Ω part. Type the value your calculation produced — plain ohms or engineering shorthand such as 4.7k, 4k7, 2M2 or 0R47 — pick a series, and the tool returns the closest standard value in any decade. It reports the signed percentage error of the adopted value against what you asked for, lists the two immediate neighbours below and the two above in the series, each with its own error (handy when rounding down is safer than rounding up, as in a current limiter or a shunt), and draws the colour code of the chosen part: four bands for E6, E12 and E24 with two significant digits, five bands for E48, E96 and E192 with three.

The tables are the literal IEC 60063 lists, which matters more than it looks. The three-digit series (E48, E96, E192) follow the geometric progression of 10 raised to n/N rounded to three significant figures, but E6, E12 and E24 predate that scheme and keep historical roundings: the exact E24 steps would be 26.1, 28.7 and 42.2, while the standard fixes 27, 30 and 43. Code that generates the series from the formula quietly emits values no distributor stocks. Worked example: 4600 Ω in E24 returns 4700 Ω at +2.17%, with 4300 Ω (−6.52%) and 5100 Ω (+10.87%) as the immediate neighbours. The search crosses decade boundaries, so 9.8 Ω in E12 correctly lands on 10 Ω (+2.04%) instead of 8.2 Ω (−16.3%). Even the famous E192 oddball is in the table: 920, where the formula says 919.5.

What this page does not do: it will not check power rating, will not propose series or parallel combinations (which often land closer to the target than any single part), and knows nothing about temperature coefficient or actual distributor stock — a value belonging to the series does not mean it is made in every package and wattage. The error shown compares nominal values only; the physical part still drifts within the series tolerance, from ±20% in E6 down to ±0.5% in E192, and in the worst case the two deviations add up. In the colour code, E6 deliberately shows an empty fourth position: 20% parts carry no tolerance band. On input, the letter in the shorthand acts as both decimal point and multiplier — R means 1, k means a thousand, M means a million. Both M and m are read as mega here; milliohms are outside the scope of a standard-value picker.