Resistor Color Code Calculator — 4, 5 & 6 Band + Reverse | StudentCalcs

Resistor Color Code Calculator

Decode any 4, 5 or 6 band resistor from its color bands, or reverse a resistance value back into bands. See a live resistor, tolerance range, temperature coefficient and the nearest standard E-series value.

Resistance
Why it is better

More than a color chart

Live resistor

A real resistor graphic updates as you pick bands, so you can match it against the part in your hand.

Reverse mode

Type any resistance and tolerance and get the exact color bands back, plus the nearest buyable value.

E-series & range

Shows tolerance min/max range and flags the nearest E12/E24/E96 standard value, which most tools skip.

How to read a resistor color code

Resistors use colored bands to encode their value. Reading left to right, the first bands are significant digits, the next is a multiplier (a power of ten), and the last is the tolerance. This resistor color code calculator supports every common layout and also works in reverse.

  • 4-band: digit, digit, multiplier, tolerance. Example: brown, black, red, gold = 1 kΩ ±5%.
  • 5-band: digit, digit, digit, multiplier, tolerance, for tighter precision.
  • 6-band: same as 5-band plus a temperature coefficient (ppm/K) band.

Resistor color code chart

ColorDigitMultiplierTolerance

What makes this calculator different

Most online tools only decode bands into a number. This one adds a live resistor drawing, a full reverse mode (value to bands), the tolerance min/max range in real ohms, the temperature coefficient for 6-band parts, and an E-series check so you know whether the value is a real, purchasable standard resistor.

Quick memory trick

A classic mnemonic for the digit colors (black, brown, red, orange, yellow, green, blue, violet, grey, white) is "B B ROY of Great Britain had a Very Good Wife". Black is 0 and white is 9.

FAQ

Frequently asked questions

How do you read a resistor color code?
First bands are significant digits, the next band is the multiplier (power of ten) and the last is tolerance. A 5-band uses three digits, a 6-band adds a temperature coefficient band.
What does a gold or silver band mean?
As a multiplier, gold is ×0.1 and silver is ×0.01. As tolerance, gold is ±5% and silver is ±10%.
Difference between 4, 5 and 6 band?
4-band gives two significant digits, 5-band gives three for tighter precision, and 6-band adds a temperature coefficient (ppm/K) band.
Can it turn a value into color bands?
Yes. Switch to "Value to bands", type the resistance and tolerance, and it draws the matching bands and shows the nearest standard value.
What are E12 and E24 series values?
Standard preferred resistor values: E12 has 12 per decade (10%), E24 has 24 per decade (5%). The tool flags the nearest one so you pick a real resistor.
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