Resistor Color Code Calculator

Resistors use colored bands to indicate their resistance value. Each color represents a digit (0-9), a multiplier (power of 10), or a tolerance percentage. Reading bands left to right gives the resistance value. Worked example: brown-black-red-gold = 1 (brown), 0 (black), x100 (red) = 1000 ohm = 1 kohm with +/-5 percent tolerance, so the real value lies between 950 and 1050 ohm. A 4.7 kohm 5-band part reads yellow-violet-black-brown-gold: 4, 7, 0, x10, +/-5 percent, showing how the extra digit band refines precision readings beyond the classic 4-band code.

1. 1

   Step 1

   Select the number of bands (4 or 5)

2. 2

   Step 2

   Choose colors for each band from the dropdown

3. 3

   Step 3

   The calculator displays the resistance value

4. 4

   Step 4

   View the tolerance range for the resistor

• 1

  4-band: 2 digits + multiplier + tolerance

• 2

  5-band: 3 digits + multiplier + tolerance (precision resistors)

• 3

  Gold multiplier = 0.1, Silver multiplier = 0.01

• 4

  Tolerance: Gold = 5%, Silver = 10%, Brown = 1%

• Reading bands in wrong direction (start from the side with bands closer together)

• Confusing brown and red, or orange and yellow

• Mixing up gold/silver tolerance vs. multiplier bands

• Not accounting for tolerance when selecting resistors