Resistor Color Code Calculator — 4-Band & 5-Band
Select the color bands printed on a resistor — from left to right — to instantly decode the resistance value in ohms, kilohms or megohms, plus the tolerance range. Supports both 4-band (standard) and 5-band (precision) resistors.
Number of bands
Band 1 (1st digit)
Band 2 (2nd digit)
Band 3 (multiplier)
Band 4 (tolerance)
How does this calculator work?
A resistor's value is encoded in colored bands: digit bands combine into a base number, then multiplied by the multiplier band, with the last band showing tolerance. 4-band = 2 digits + multiplier + tolerance; 5-band = 3 digits + multiplier + tolerance. Select your colors above to decode resistance and the min/max range.
Formula
How this is calculated
Resistors use a standard color code because their bodies are too small to print numbers legibly. Each color maps to a digit (0–9) and a multiplier power of ten. In a 4-band resistor the first two bands are the significant digits, the third band is the multiplier, and the fourth band (usually gold or silver) is the tolerance. In a 5-band precision resistor there are three significant-digit bands, followed by a multiplier and a tolerance band.
To decode: read the digit value of each band, combine them into the base number, then multiply by the multiplier. For example, Brown–Black–Red–Gold encodes (1, 0) × 100 = 1000 Ω = 1 kΩ ±5%. The tolerance band tells you the guaranteed accuracy — a ±5% (gold) 1 kΩ resistor measures between 950 Ω and 1050 Ω.
Memory tip: "Better Be Right Or Your Great Big Venture Goes Wrong" maps Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White to digits 0–9. Multipliers beyond White (gold = ÷10, silver = ÷100) are used for sub-ohm resistors.
Frequently asked questions
Start from the end closest to the first band. The tolerance band (gold or silver) is usually spaced slightly further from the other bands and is always on the right when the resistor is held correctly. If unsure, measure with a multimeter and decode both ways — only one will match.
Tolerance is the guaranteed accuracy. A 1 kΩ ±5% resistor will measure between 950 Ω and 1050 Ω. Precision 5-band resistors with brown (±1%) or red (±2%) tolerance bands are needed in sensitive analog circuits.
Some 6-band resistors add a sixth band for temperature coefficient (parts per million per °C, or PPM/°C). The standard decoder above covers 4- and 5-band resistors; 6-band decoding uses the same first five rules with the sixth band indicating temperature stability.
Also known as
TG we-Calculate Editorial Team. (2026). Resistor Color Code Calculator — 4-Band & 5-Band [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/resistor-color-code-calculator
TG we-Calculate Editorial Team. "Resistor Color Code Calculator — 4-Band & 5-Band." TG we-Calculate. 2026. https://we-calculate.com/calculator/resistor-color-code-calculator.
TG we-Calculate Editorial Team, "Resistor Color Code Calculator — 4-Band & 5-Band," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/resistor-color-code-calculator
@misc{wecalculate_resistor_color_code_calculator, title = {Resistor Color Code Calculator — 4-Band & 5-Band}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/resistor-color-code-calculator}}, year = {2026}, note = {TG we-Calculate} }
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