Resistor Color Code Calculator

Decode resistor values from 4, 5, or 6 color bands, or find the color code for any resistance value and tolerance.

Mode

Band count

1st digit

2nd digit

Multiplier

Tolerance

Resistance1000 Ω

Tolerance±5%

Range950 – 1050 Ω

This calculator is for educational purposes only. Always consult a licensed electrician and local electrical codes before installation or repair.

How It Works

1
Choose the mode and band count
Pick "Colors → Value" to decode a physical resistor, or "Value → Colors" to find the color code for a known resistance. Select 4, 5, or 6 bands.
2
Select each band color in order
Read the resistor left to right with the tolerance band on the right. Pick each color from the dropdowns. The calculator only offers colors that are valid for each band's role.
3
Read the resistance, tolerance, and range
The calculator shows the nominal resistance, the tolerance percentage, and the allowable min and max values. For six-band resistors it also displays the temperature coefficient.

Resistor Color Code: Four Stripes, One Standard Since 1930

A quarter-watt resistor is about the size of a grain of rice. Printing "4.7 kΩ ±5%" on one legibly isn't possible, so in the 1920s the Radio Manufacturers Association chose ten colors instead. By 1930 the first radios using color-coded resistors shipped, and engineers have been decoding the stripes ever since. The scheme was internationally standardized in 1952 as IEC 62 and is maintained today as IEC 60062. Ten colors map to digits zero through nine: black, brown, red, orange, yellow, green, blue, violet, gray, white. Gold and silver never act as digits. They only appear as multipliers (×0.1 and ×0.01) or as tolerance bands (±5% and ±10%). Four-band resistors encode two digits, a power-of-ten multiplier, and a tolerance. Five-band and six-band resistors add a third significant digit for precision parts, and the sixth band specifies a temperature coefficient in parts per million per kelvin. Tolerance colors follow a separate table: brown ±1%, red ±2%, green ±0.5%, blue ±0.25%, violet ±0.1%, gray ±0.05%. If a resistor has no tolerance band, the part is ±20%. Standard resistance values follow the E-series of preferred numbers, geometric progressions defined as 10^(1/n). E24 (±5%) has 24 values per decade; E96 (±1%) has 96. The orientation rule: hold the resistor so the tolerance band is on the right. Gold or silver at one end is a giveaway, since neither color is valid as a digit.

Need a full reference? Our resistor color code chart guide covers 4-band, 5-band, and 6-band reading, SMD codes, and E-series preferred values.

Common pitfalls

Reading the bands from the wrong end. Hold the resistor so the tolerance band (gold, silver, brown, red, green, blue, violet, or gray) is on the right. On many parts there is a visible gap between the last digit/multiplier group and the tolerance band; always read away from that gap.
Confusing 4-band and 5-band parts. A 4-band shows two digits + multiplier + tolerance; a 5-band shows three digits + multiplier + tolerance. Reading a 5-band resistor as 4-band shifts everything: a 4.7 kΩ 1% (yellow-violet-black-brown-brown) reads as 47 Ω 1% if you drop the third digit.
Treating gold/silver as a digit. Gold and silver are only valid as multipliers (×0.1, ×0.01) or tolerance bands (±5%, ±10%). Any resistor showing gold or silver in the first or second band position has been misread.
Assuming precision resistors are always 5-band. Surface-mount 0805/0603 precision parts use three- or four-digit numeric codes (e.g. 4701 = 4.70 kΩ, 01C = 10.0 kΩ EIA-96). Color codes are for through-hole parts.
Measuring with a multimeter in-circuit and thinking the resistor is bad. Any parallel paths (ICs, other resistors, capacitors across DC) skew the reading. Lift one lead or desolder before verifying value against the band code.

Frequently Asked Questions

How do I read a resistor color code?

Hold the resistor so the tolerance band (typically gold or silver) is on the right. Read colors left to right. On a 4-band resistor: first two bands are digits, third is the multiplier (power of 10), fourth is tolerance. Example: red-red-red-gold = 22 × 100 = 2,200 Ω ±5%.

What's the difference between 4-band, 5-band, and 6-band resistors?

4-band resistors have 2 significant digits + multiplier + tolerance (typical ±5% or ±10%). 5-band has 3 significant digits + multiplier + tolerance, allowing precision resistors (±1% or tighter). 6-band adds a temperature coefficient band (ppm/K) for high-stability applications such as precision instrumentation.

What is the standard color code sequence?

Per IEC 60062: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Gray=8, White=9. Multipliers follow the same order for powers of 10, with Gold=×0.1 and Silver=×0.01 for fractional values. A common mnemonic is 'Bad Boys Ring Our Young Girls But Violet Generally Wins' — though anything memorable works.

How accurate is the tolerance value?

The tolerance band tells you the maximum allowed deviation from nominal: ±5% means a 1000 Ω resistor can measure anywhere from 950 to 1050 Ω. Commercial resistors are typically ±5% (E24 series) or ±1% (E96 series). For precision work, measure each resistor with a calibrated ohmmeter rather than relying on the tolerance band.

Can I decode 3-band resistors?

3-band resistors have 2 digits + multiplier, with no tolerance band. They are assumed to be ±20% tolerance. This tool focuses on the more common 4, 5, and 6-band variants, but you can treat a 3-band resistor as a 4-band with a 'none' tolerance band (=±20%).

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