Resistor Color Code Calculator
The resistor color code calculator decodes the resistance value from the colored bands on a resistor, or works the other way to find the right color bands for a value you already know. It is built for electronics students, hobbyists, and engineers who need an answer in seconds instead of reaching for a printed chart.
Pick 4 Bands, 5 Bands, or 6 Bands to match your part, then switch between Color → Value and Value → Color depending on whether you are reading a resistor or designing for one. Results include the resistance, tolerance, and tolerance range, with automatic Ω / kΩ / MΩ / GΩ formatting.
How to Use
Reading a Resistor (Color → Value)
Choose the band count
Select 4, 5, or 6 Bands to match the resistor in front of you.
Click each band
Click a band on the resistor diagram to open its color palette, which lists every available color with its digit, multiplier, or tolerance value.
Read the result
The resistance, tolerance, and the minimum-to-maximum tolerance range appear instantly below the resistor.
Finding Color Bands (Value → Color)
Switch the tab
Open the Value → Color tab to convert a known resistance into its band colors.
Enter value and options
Type the Resistance Value, pick the unit (Ω, kΩ, or MΩ) and tolerance, and for 6-band parts choose a temperature coefficient.
See the bands
The resistor diagram updates automatically. If the value is not a standard part, the tool suggests the nearest E24 value you can apply in one click.
Using the Color Reference Table
The reference table at the bottom is a quick lookup for every resistor color code. Each row shows the color along with its digit, multiplier, tolerance, and temperature coefficient.
Features
Decode 4, 5, and 6-Band Codes
Read the resistance from color bands on 4-band, 5-band, and 6-band resistors, covering the parts you meet most.
Interactive Resistor Diagram
A realistic resistor with clickable bands lets you match exactly what you see on the physical component.
Color Palette With Values
Each band's dropdown shows every color alongside its digit, multiplier, or tolerance, so the meaning is always clear.
Value → Color Conversion
Enter a resistance and tolerance to see the matching color bands rendered on a visual resistor.
Automatic Unit Formatting
Results display in Ω, kΩ, MΩ, or GΩ automatically, so the value is always clean and readable.
Tolerance Range Display
In Color → Value mode the tool shows the actual minimum and maximum resistance based on the tolerance band.
Temperature Coefficient
For 6-band precision resistors, set and read the temperature coefficient band in ppm/°C.
E24 Series Validation
Non-standard values flag a warning and suggest the nearest E24 standard value, ready to apply with one click.
Complete Color Reference
A full table maps every color to its digit, multiplier, tolerance, and temperature coefficient for instant lookup.
Dark Mode Support
A built-in dark theme keeps the resistor diagram and tables easy to read in low light.
Frequently Asked Questions
How do you read a 4-band resistor?
A 4-band resistor has two digit bands, a multiplier, and a tolerance band. Read the first two colors as digits, then multiply by the third band — for example brown-black-red is 1, 0, ×100, giving 1,000 Ω (1 kΩ). The fourth band sets the tolerance. In this tool, click each band on the diagram and the value appears instantly.
How do you read a 5-band resistor?
A 5-band resistor uses three digit bands instead of two, then a multiplier and a tolerance band. Read the first three colors as digits and multiply by the fourth band. The extra digit gives higher precision than a 4-band part. Select 5 Bands at the top of the tool and decode each band the same way.
What does each color band mean?
Each color maps to a fixed value: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, white 9. The same colors act as multipliers (powers of ten) and as tolerance or temperature-coefficient bands. The color reference table in the tool lists every value at a glance.
Which end do you start reading from?
On a physical resistor the tolerance band — often gold or silver, or the band with the widest gap from the rest — sits on the right, so you start reading from the opposite end. In this calculator the leftmost band is always the first digit, so just orient the resistor with the tolerance band on the right.
What is the tolerance band (gold or silver)?
The tolerance band shows how far the real resistance may differ from its nominal value. As tolerance bands, gold means ±5% and silver means ±10%. The same gold and silver colors also work as multipliers — gold ×0.1 and silver ×0.01 — for sub-ohm resistors. The tool shows the resulting minimum-to-maximum range for you.
What is the temperature coefficient band?
The 6th band, found only on precision 6-band resistors, indicates how much the resistance drifts with temperature, measured in ppm/°C (parts per million per degree Celsius). A lower number means better stability. Switch to 6 Bands to read or set this band.
What happens if my value is not a standard resistor value?
In Value → Color mode the tool checks your entry against the standard E24 series. If it does not match, it shows a warning and suggests the nearest E24 value, which you can apply with a single click. The E24 series covers the resistor values that are most commonly manufactured.
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