Calculators

Resistor Color Code Calculator

Identify the resistance and tolerance of a resistor from its color bands, or calculate the color bands required for a known resistance value. Supports 4-band and 5-band resistors.

What Is a Resistor Color Code?

Through-hole resistors commonly use colored bands to indicate their resistance value and tolerance.

Each color represents a numerical digit or multiplier. The final band normally indicates the resistor tolerance. 

4-Band Resistor

Band 1 ā†’ First digit
Band 2 ā†’ Second digit
Band 3 ā†’ Multiplier
Band 4 ā†’ Tolerance

Resistor Color Code Chart

Color Digit Multiplier Common Tolerance
Black 0 Ɨ1 ā€”
Brown 1 Ɨ10 Ā±1%
Red 2 Ɨ100 Ā±2%
Orange 3 Ɨ1,000 ā€”
Yellow 4 Ɨ10,000 ā€”
Green 5 Ɨ100,000 Ā±0.5%
Blue 6 Ɨ1,000,000 Ā±0.25%
Violet 7 Ɨ10,000,000 Ā±0.1%
Grey 8 Ɨ100,000,000 Ā±0.05%
White 9 Ɨ1,000,000,000 ā€”
Gold ā€” Ɨ0.1 Ā±5%
Silver ā€” Ɨ0.01 Ā±10%

4-Band Resistor Calculator

Use this calculator when the resistor has four colored bands.

Select the four resistor bands.

Example ā€” Brown, Black, Red, Gold

Consider a resistor with the following four bands: 

Brown  Black  Red  Gold

  1      0    Ɨ100   Ā±5%

The resistance is: 

10 Ɨ 100 = 1,000 Ī©

= 1 kĪ© Ā±5%

The actual resistance can therefore be within the tolerance range specified by the Ā±5% tolerance.

5-Band Resistor Calculator

Five-band resistors use three significant digits, followed by the multiplier and tolerance. 

Band 1 ā†’ First digit
Band 2 ā†’ Second digit
Band 3 ā†’ Third digit
Band 4 ā†’ Multiplier
Band 5 ā†’ Tolerance
Select the five resistor bands.

Example ā€” Brown, Black, Black, Red, Brown

For a five-band resistor: 

Brown  Black  Black  Red  Brown

  1      0      0    Ɨ100   Ā±1%

Therefore: 

100 Ɨ 100 = 10,000 Ī©

= 10 kĪ© Ā±1%

Calculate Color Bands from Resistance

You can also enter a resistance value and determine the corresponding four-band resistor color code.

Enter a resistance value.

Common Resistor Examples

Resistance 4-Band Code
100 Ī© Brown ā€“ Black ā€“ Brown
220 Ī© Red ā€“ Red ā€“ Brown
330 Ī© Orange ā€“ Orange ā€“ Brown
470 Ī© Yellow ā€“ Violet ā€“ Brown
1 kĪ© Brown ā€“ Black ā€“ Red
2.2 kĪ© Red ā€“ Red ā€“ Red
4.7 kĪ© Yellow ā€“ Violet ā€“ Red
10 kĪ© Brown ā€“ Black ā€“ Orange
47 kĪ© Yellow ā€“ Violet ā€“ Orange
100 kĪ© Brown ā€“ Black ā€“ Yellow
1 MĪ© Brown ā€“ Black ā€“ Green

How to Read a Resistor

  1. Hold the resistor so the tolerance band is normally on the right.
  2. Read the first significant digit.
  3. Read the second significant digit.
  4. Read the multiplier.
  5. Read the tolerance band.
  6. Calculate the resistance.

The tolerance band is often separated from the other bands by a larger gap, which helps identify the reading direction.

Resistor Tolerance

Tolerance specifies how much the actual resistance can differ from the nominal resistance.

For example, a 1 kĪ© resistor with Ā±5% tolerance has a nominal value of 1,000 Ī© and a tolerance of 50 Ī©. 

Minimum = 950 Ī©

Nominal = 1,000 Ī©

Maximum = 1,050 Ī©

Gold and Silver Bands

Gold and silver have special meanings in resistor color coding.

  • Gold multiplier = Ɨ0.1
  • Silver multiplier = Ɨ0.01
  • Gold tolerance = Ā±5%
  • Silver tolerance = Ā±10%

Gold and silver are not used as ordinary significant-digit colors in the same way as black through white.

Resistor Color Code Mnemonic

A commonly used mnemonic for remembering the numerical color sequence is: 

Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Grey
White

0 1 2 3 4 5 6 7 8 9

Resistor Color Code Troubleshooting

If the measured resistance does not match the color bands, consider:

  • The resistor may have been read in the wrong direction.
  • The resistor may have a damaged or faded band.
  • The resistor may be a 5-band rather than a 4-band type.
  • The measured value may be affected by in-circuit components.
  • The resistor may have failed.
  • The color may have been incorrectly identified.

Measuring a Color-Coded Resistor

A multimeter can be used to verify the resistance value.

  1. Turn off the circuit.
  2. Discharge capacitors where necessary.
  3. Set the multimeter to resistance mode.
  4. Place the probes across the resistor.
  5. Compare the measured value with the color-code value.

For an accurate measurement, one terminal may need to be disconnected from the circuit.

SMD Resistors

Surface-mount resistors normally do not use the traditional colored bands.

Instead, many SMD resistors use numerical or alphanumeric markings.

Examples include: 

103 ā†’ 10 kĪ©

472 ā†’ 4.7 kĪ©

100 ā†’ 10 Ī©

SMD marking systems can vary, so the marking convention should be checked when necessary.

Important Notes

  • Black through white represent digits 0 through 9.
  • Gold and silver have special multiplier and tolerance meanings.
  • Four-band resistors use two significant digits.
  • Five-band resistors use three significant digits.
  • The multiplier determines the final resistance magnitude.
  • The tolerance band specifies the allowed resistance variation.
  • Always verify unusual or unclear markings with a multimeter.
  • In-circuit resistance measurements may not equal the resistor's actual value.

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