Resistor colour code

The value from the bands, with the band count asked rather than guessed

It runs entirely in this browser tab: the numbers you type are never uploaded, and the tool makes no network request while it works. Open your browser's network panel and try it — nothing leaves the page.

Settings

How many bands: The same three colours read as four bands or as five differ by a factor of ten, so this is asked rather than guessed. Choices: Four bands, Five bands.

How to use it

Paste your text into the box above, or open a file.
Adjust the settings beside it until the result is what you wanted.
Copy the result, or save it as a file. The result updates as you type.

Questions

Can I build from this?: Not from this alone. The cable, beam and rainwater tools each say so on their own result: they are arithmetic, and what may be built is decided by the wiring, structural and water regulations where the work is — none of which this page has read.
Why does a tool refuse a number it could clearly calculate?: Because several of these formulas are fits rather than laws. Wind chill is defined at 10 °C or colder in a wind over 4.8 km/h, the heat index from 27 °C up, and the barometric formula to the top of the troposphere. Outside those the arithmetic still runs and the answer means nothing, so the tool says which rather than printing it.
Does anything here use floating point?: No. Every figure is exact decimal arithmetic, which is why 0.1 + 0.2 is 0.3 here and a unit conversion comes back to where it started. The one place a ceiling exists — how many digits an exponent may carry — is stated rather than reached silently.
Is what I type uploaded anywhere?: No. This page carries the whole tool as WebAssembly and runs it on your own device. A measurement is somebody's experiment and a load is somebody's building; none of it is sent anywhere.

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Resistor colour code

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