How do I know which end is the first band?

Bands are grouped near one end with a wider gap before the tolerance band. The tolerance band is usually gold or silver; start reading from the opposite end.

What's the temperature coefficient band for?

It tells you how much the resistance drifts per °C — important in precision analog circuits. Common: brown = 100 ppm/°C, red = 50 ppm/°C, blue = 10 ppm/°C.

My color looks like green or blue — how do I tell?

Real bands on real resistors are notoriously ambiguous (especially blue/violet, brown/red). Measure with a multimeter to confirm. The color code is an estimate; the multimeter is ground truth.

Why do my five bands give a weird-looking number?

On 5-band parts, swapping the first and last (tolerance) bands is a classic mistake — you'd read it backwards. If the result has weird precision (like 12345.6 Ω), try reading from the other end.

Resistor Color Code Calculator

Through-hole resistors encode their value in colored bands. 4-band: two significant digits + multiplier + tolerance. 5-band: three significant digits + multiplier + tolerance (precision parts). 6-band: 5-band plus a temperature coefficient. This tool lets you pick each band's color from a visual selector and shows the computed resistance, tolerance range, and a live preview of the resistor body. Useful when you've pulled a part from a bin and can't read the markings off a datasheet.

—

Band 1 (digit)Band 2 (digit)MultiplierTolerance

Resistance

22 Ω

±10% · Range: 19.8 Ω … 24.2 Ω

Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9. Gold/silver multipliers (×0.1, ×0.01) and tolerances (±5%, ±10%).

How to use

Pick the number of bands (4 for common, 5 for precision, 6 for high-stability).
Click each band dropdown and choose its color.
The value, tolerance range, and color preview update instantly.

Frequently asked questions

How do I know which end is the first band?: Bands are grouped near one end with a wider gap before the tolerance band. The tolerance band is usually gold or silver; start reading from the opposite end.
What's the temperature coefficient band for?: It tells you how much the resistance drifts per °C — important in precision analog circuits. Common: brown = 100 ppm/°C, red = 50 ppm/°C, blue = 10 ppm/°C.
My color looks like green or blue — how do I tell?: Real bands on real resistors are notoriously ambiguous (especially blue/violet, brown/red). Measure with a multimeter to confirm. The color code is an estimate; the multimeter is ground truth.
Why do my five bands give a weird-looking number?: On 5-band parts, swapping the first and last (tolerance) bands is a classic mistake — you'd read it backwards. If the result has weird precision (like 12345.6 Ω), try reading from the other end.

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