How to use the resistor color code calculator
- 1 Choose 4, 5 or 6 bands.
- 2 Pick the digit band colors (two for 4-band, three for 5- and 6-band).
- 3 Pick the multiplier and tolerance colors, and the temperature coefficient for 6 bands.
- 4 Read the resistance, tolerance and range.
Worked example
A 4-band resistor with yellow, violet, red and gold bands. Yellow (4) and violet (7) give 47, and red multiplies by 100: 4,700 Ω = 4.7 kΩ. Gold means ±5%, so the actual value is between 4.465 kΩ and 4.935 kΩ.
Reading resistors reliably
- Find the tolerance band first and read from the other end.
- Check under good light: brown, red and orange look alike.
- Confirm with a multimeter when in doubt.
- Three bands means ±20%.
Convert power units with the Power Converter, energy with the Energy Converter, and frequency with the Frequency Converter.
How it works: The digit bands form a number, two digits for 4-band resistors and three for 5- and 6-band resistors. It is multiplied by ten to the power of the multiplier band, and the tolerance band sets the minimum and maximum values the part can really have in your circuit.
Features
4, 5 and 6 bands
All common through-hole resistor codes.
Tolerance range
Minimum and maximum actual resistance.
Readable units
Ω, kΩ, MΩ and GΩ chosen automatically.
When to use it
Electronics projects
Check resistors before soldering.
Learning electronics
Practice reading color codes.
Repairing circuits
Identify a resistor to replace.
Number systems
Work with scientific notation using the Scientific Notation Converter.
Related Science tasks
Frequently asked questions
How do you read a resistor color code?
Hold the resistor with the tolerance band (often gold or silver) on the right. Read the digit bands left to right, then multiply by the multiplier band's value.
What is yellow, violet, red, gold?
4 and 7 give 47; red multiplies by 100: 4,700 Ω, or 4.7 kΩ, with ±5% tolerance from the gold band.
What do the colors stand for?
Black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, white 9. Gold multiplies by 0.1 and silver by 0.01.
Is there a mnemonic for resistor colors?
"Big Brown Rabbits Often Yield Great Big Vegetables Growing Wild" for black, brown, red, orange, yellow, green, blue, violet, gray, white.
What is the difference between 4-band and 5-band resistors?
4-band resistors have two digits; 5-band precision resistors have three digits, allowing more exact values and usually tighter tolerance.
What does the 6th band mean?
The temperature coefficient: how much the resistance changes with temperature, in parts per million per kelvin (ppm/K).
What does tolerance mean?
How far the real resistance can be from the marked value. A 4.7 kΩ ±5% resistor can be anywhere from 4.465 to 4.935 kΩ.
Which end do I start reading from?
The end with the band closest to the edge. The tolerance band is usually set apart with a wider gap.
What if there are only 3 bands?
It is a 4-band code with no tolerance band, meaning ±20%. Choose None as the tolerance.
Do surface-mount resistors use color codes?
No. Surface-mount resistors use printed number codes, such as 472 for 4.7 kΩ.
What are standard resistor values?
Resistors come in E-series values such as E12 (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) and E24 for tighter tolerances.
What color is a 10k resistor?
Brown, black, orange: 1, 0 and ×1,000 = 10 kΩ, followed by the tolerance band.
What color is a 220 ohm resistor?
Red, red, brown: 2, 2 and ×10 = 220 Ω.
What color is a 1k resistor?
Brown, black, red: 1, 0 and ×100 = 1 kΩ.
What is a zero-ohm resistor?
A single black band: a jumper link in resistor form.
Built and reviewed by Hamza Farooq, founder and lead developer
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