Instant Calculations
Calculate resistor values immediately whenever you select or change a color band.
Free Electronics Calculator
Resistor Color Code Calculator
Decode 4-band, 5-band, and 6-band resistor color codes instantly. Select each color band to calculate resistance, tolerance, and temperature coefficient.
Calculate Resistor Value
Select the resistor type and choose the colors in left-to-right order.
Calculated resistance
1.2 kΩ ±5%
Exact Value
1,200 Ω
Tolerance
±5%
Minimum Value
1.14 kΩ
Maximum Value
1.26 kΩ
Temperature Coefficient
10 ppm/°C
Resistor Type
4-Band
Why Use This Resistor Calculator?
Get accurate resistor values without manually memorizing every color, multiplier, and tolerance combination.
Multiple Band Types
Decode common 4-band, precise 5-band, and temperature-rated 6-band resistors.
Resistance Range
View the nominal, minimum, and maximum resistance according to the selected tolerance.
How to Use the Resistor Color Code Calculator
A resistor color code uses colored bands to represent its electrical resistance and accuracy. This calculator converts those bands into a readable resistance value.
- Select whether your resistor has four, five, or six bands.
- Choose each color in the same order shown on the physical resistor.
- Select the multiplier and tolerance colors.
- For a six-band resistor, choose the temperature coefficient.
- Review the resistance value and its possible minimum and maximum range.
How to Identify the Reading Direction
Start reading from the end where the color bands are closer together. The tolerance band is often separated by a slightly larger gap and is commonly gold, silver, brown, or red.
Understanding a 4-Band Resistor
A four-band resistor contains two significant digits, one multiplier, and one tolerance band. For example, brown, red, red, and gold represent:
- Brown: first digit 1
- Red: second digit 2
- Red multiplier: ×100
- Gold tolerance: ±5%
The final value is 12 × 100, which equals 1,200 ohms or 1.2 kilo-ohms with ±5% tolerance.
Understanding 5-Band and 6-Band Resistors
Five-band resistors use three significant digits, making them more precise than standard four-band resistors. A six-band resistor adds a temperature coefficient band, which describes how much the resistance may change as temperature changes.
Important:
Always confirm the physical resistor's reading direction before
entering its colors. Reversing the bands can produce a completely
different result.
Frequently Asked Questions
Common questions about resistor colors, values, and tolerance bands.
Read the first two bands as significant digits. The third band is the multiplier, while the fourth band represents tolerance.
A four-band resistor uses two significant digits. A five-band resistor uses three significant digits, allowing it to show more precise resistance values.
Gold represents a multiplier of 0.1 when used as the multiplier band. When used as the tolerance band, it represents ±5%.
Silver represents a multiplier of 0.01 or a tolerance of ±10%, depending on the band's position.
The sixth band usually displays the temperature coefficient in parts per million per degree Celsius, written as ppm/°C.
Tolerance indicates how far the resistor's actual value may differ from its stated value. A 1,000-ohm resistor with ±5% tolerance may measure between 950 and 1,050 ohms.