Resistor color code calculator
Pick colours to read the value, or type a value to see its colours. Both stay in sync as you type.
Indicative calculation; verify before use.
Printable resistor color code chart (4, 5 and 6 bands, E12 and E24), print or save as PDF
Value
Bands
How it works
Read from the end with the bands grouped together; the tolerance band usually sits apart. Example: yellow–violet–red–gold = 47 × 10² Ω = 4.7 kΩ ±5 %. A resistor with only three bands has no tolerance band and is ±20 %.
Typing a value uses the RKM notation from the same standard: the letter replaces the decimal point (4K7 = 4.7 kΩ, 2R2 = 2.2 Ω, R47 = 0.47 Ω).
"Nearest standard value" is measured on a logarithmic scale (ratio, not difference), because the E-series are spaced geometrically: E12 has 12 values per decade (about ±10 % steps), E24 has 24 (±5 %), E96 has 96 (±1 %).
Colour table
| Colour | Digit | Multiplier | Tolerance | TCR ppm/K |
|---|
Sources (checked 2026-10-30):
- Colour bands, R = digits × 10^multiplier, tolerance and TCR (IEC 60062:2016, as tabulated): https://en.wikipedia.org/wiki/Electronic_color_code. Grey tolerance is ±0.01 % in IEC 60062:2016; older EIA documents and some datasheets use ±0.05 %, so check the datasheet for grey.
- RKM notation (4K7, 2R2, R47): https://en.wikipedia.org/wiki/RKM_code
- E12/E24/E96 standard values (IEC 60063, as tabulated): https://en.wikipedia.org/wiki/E_series_of_preferred_numbers