Resistor Color Code Calculator
Decode resistor bands or find the bands for any resistance value.
The Resistor Color Code Calculator works both ways: decode the color bands of a 4- or 5-band resistor into its value and tolerance, or type a resistance and find the bands that represent it.
Resistors are too small for printed numbers, so their values ride on colored bands — a color language every electronics hobbyist and technician reads daily. Brown-black-red-gold is 1,000 Ω at 5%; red-violet-green is 2.7 MΩ. The decoder handles both common band counts and both multiplier and digit colors, including gold and silver multipliers.
The encoder finds the closest standard representation for any value you type. Band color swatches render beside each picker so you never guess a hue. Everything runs locally in your browser.
Band 1
Band 2
Multiplier
Tolerance
2.70 MΩ
tolerance ±5%
4-band: 2 digits, multiplier, tolerance. Digit colors: black 0 … white 9; multiplier colors include gold (×0.1) and silver (×0.01). Read bands left to right with the tolerance band last.
How to use the Resistor Color Code Calculator
- Choose decode or encode mode.
- Decode: pick each band's color from the selectors and read the value.
- Switch between 4- and 5-band formats.
- Encode: type an ohms value and tolerance, read the bands.
- Verify with a multimeter when precision matters.
Frequently asked questions
How do I read a 4-band resistor?
Band 1 and 2 are digits, band 3 is the multiplier (how many zeros), band 4 is tolerance. Brown-black-red-gold: 1, 0, ×100 → 1,000 Ω, ±5%. 5-band resistors add a third digit for more precision.
Which color means what?
Digits: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Gold and silver act as multipliers (×0.1, ×0.01) or tolerances (±5%, ±10%); brown tolerance is ±1%.
How do I know which end to read from?
The tolerance band (gold, silver or a wider gap) is on the right; read toward it from the other side. When unsure, measure with a multimeter — the definitive check.
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