Resistor Color Code Calculator
Read resistor colour bands into a value, or a value into its bands.
What is Resistor Color Code?
Axial resistors are marked with coloured bands instead of numbers because a printed value would be unreadable at that size and would rub off. The code is positional: two or three significant digits, a multiplier that is a power of ten, a tolerance band, and on precision parts a sixth band for the temperature coefficient. This page reads bands into a value and writes a value back into bands, drawing the part as it would look.
How it works
The first two bands (or three, for 5 and 6-band parts) are digits 0–9, black to white. The next band multiplies by a power of ten — gold and silver are the negative two powers, ×0.1 and ×0.01 — and the band after that is the tolerance. Only colours that are legal in a position can be selected there, so an impossible strip cannot be assembled, and a 4-band part snaps to E24 because two digits cannot express an E96 value. Reading it back gives the value, the ±% tolerance and the range the part is guaranteed within.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.