Calculate The Following Resistor Color Code

Resistor color codes are a standardized way to indicate the resistance value and tolerance of a resistor. This guide explains how to read and calculate resistor color codes, including 4-band, 5-band, and 6-band resistors.

How to read resistor color codes

The color bands on a resistor follow a specific pattern that encodes its resistance value and tolerance. Here's how to interpret them:

4-band resistor

First band: First significant digit
Second band: Second significant digit
Third band: Multiplier (power of 10)
Fourth band: Tolerance

5-band resistor

First band: First significant digit
Second band: Second significant digit
Third band: Third significant digit
Fourth band: Multiplier (power of 10)
Fifth band: Tolerance

6-band resistor

First band: First significant digit
Second band: Second significant digit
Third band: Third significant digit
Fourth band: Multiplier (power of 10)
Fifth band: Tolerance
Sixth band: Temperature coefficient (ppm/°C)

Note: The color bands are typically read from left to right, starting from the end of the resistor body closest to the first band.

Resistor color code chart

Here's a reference chart for resistor color codes:

Color	Digit	Multiplier	Tolerance
Black	0	1 (10⁰)	-
Brown	1	10 (10¹)	±1%
Red	2	100 (10²)	±2%
Orange	3	1,000 (10³)	-
Yellow	4	10,000 (10⁴)	-
Green	5	100,000 (10⁵)	±0.5%
Blue	6	1,000,000 (10⁶)	±0.25%
Violet	7	10,000,000 (10⁷)	±0.1%
Gray	8	100,000,000 (10⁸)	±0.05%
White	9	1,000,000,000 (10⁹)	-
Gold	-	0.1 (10⁻¹)	±5%
Silver	-	0.01 (10⁻²)	±10%
Pink	-	-	-
Cyan	-	-	-

Calculating resistor values

The resistance value is calculated by combining the significant digits and applying the multiplier. Here's the formula:

Resistance = (Digit1 × 10 + Digit2 × 1) × Multiplier

For example, a resistor with bands brown (1), black (0), red (×100) would have a resistance of:

(1 × 10 + 0 × 1) × 100 = 10 × 100 = 1,000 ohms

For a 5-band resistor, the calculation is similar but includes a third significant digit:

Resistance = (Digit1 × 100 + Digit2 × 10 + Digit3 × 1) × Multiplier

For a 6-band resistor, the calculation is the same as for a 5-band resistor, but the sixth band indicates the temperature coefficient.

Common resistor types

Resistors come in various types, each with different characteristics:

Type	Description	Common Uses
Carbon Composition	Made of carbon powder mixed with a binder	General-purpose, low-cost applications
Metal Film	Made of a thin layer of metal on a ceramic substrate	High stability, precision applications
Wirewound	Made of a wire wound around a ceramic core	High power, high voltage applications
Thick Film	Made of a thick layer of resistive material on a ceramic substrate	Surface mount applications
Thin Film	Made of a thin layer of resistive material on a ceramic substrate	High precision, low noise applications

Tolerance and temperature coefficients

Resistors have tolerance bands that indicate the acceptable deviation from the nominal value. The temperature coefficient indicates how the resistance changes with temperature.

For most general-purpose applications, a tolerance of ±5% is acceptable. For precision applications, tolerances of ±1% or better are required.

Frequently Asked Questions

What is the difference between a 4-band and 5-band resistor?: A 4-band resistor has two significant digits and a multiplier, while a 5-band resistor has three significant digits and a multiplier. The fifth band indicates the tolerance.
How do I read a resistor with gold or silver bands?: Gold bands typically indicate a multiplier of 0.1 and a tolerance of ±5%. Silver bands indicate a multiplier of 0.01 and a tolerance of ±10%.
What does the sixth band on a 6-band resistor indicate?: The sixth band on a 6-band resistor indicates the temperature coefficient, which shows how much the resistance changes with temperature.
How do I know if a resistor is damaged?: If a resistor is damaged, it may have a broken band, a cracked body, or an unusual color. It may also have an unusual smell or be discolored.
Can I use a resistor with a higher tolerance than specified?: No, you should not use a resistor with a higher tolerance than specified in your circuit. This could cause the circuit to malfunction.