Bands
Read bands from the end with the bands grouped together, toward the lone tolerance band. Everything is computed in your browser — nothing is uploaded.
Result
Enter a resistance value greater than 0.
- Tolerance
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- Min – Max
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- Exact value
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- Band colors
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A two-way resistor color code calculator. Pick the number of bands (3, 4, or 5). In 'Colors → value' mode, choose the colors for band 1 and band 2 (plus band 3 on a 5-band resistor), the multiplier band, and the tolerance band, and it computes the resistance (Ω / kΩ / MΩ), the tolerance (±%), and the resulting minimum–maximum range. In the reverse 'Value → colors' mode, enter a resistance value (in Ω, kΩ, or MΩ) and tolerance, and it works out the matching band colors and order, drawing them onto a resistor diagram. The color mapping follows the standard code (black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9; multipliers black ×1 up to white ×1G plus gold ×0.1 and silver ×0.01; tolerances gold ±5%, silver ±10%, and so on). A 3-band resistor has no tolerance band, so it is treated as ±20%. Resistors are read with the grouped bands first and the lone tolerance band last, so this also helps when you're unsure which end to read from. Useful for electronics and kit building, sorting components, sanity-checking against a datasheet, or as a quick color-code chart. Everything is computed in your browser; the values you enter are never sent to any server or API.
How to use
- Pick the number of bands (3 / 4 / 5) and the mode (colors → value, or value → colors).
- For 'colors → value' choose each band's color; for 'value → colors' enter the resistance (Ω/kΩ/MΩ) and tolerance.
- Read off the resistance, tolerance, min–max range, and the band colors and order (nothing is sent).
FAQ
Are the values I enter sent anywhere?
No. The color-to-value and value-to-color conversions all run in your browser. The values you enter are never sent to any server or API — everything stays on your device.
Which end of a resistor do I read from?
The digit and multiplier bands are grouped toward one end, and a single band sits a little apart at the other end (the tolerance band, often gold or silver). Read from the grouped side first toward the lone tolerance band last. This tool likewise lists band 1 → multiplier → tolerance from left to right.
What's the difference between 4-band and 5-band?
A 4-band code is '2 digits + multiplier + tolerance'; a 5-band code is '3 digits + multiplier + tolerance', giving one more significant figure for higher-precision parts. A 3-band code has no tolerance band and is treated as ±20%. Switching the band count updates the inputs automatically.
What is the color-to-number chart?
Digits: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Multipliers run black ×1 up to white ×1G, plus gold ×0.1 and silver ×0.01. Tolerances include brown ±1%, red ±2%, green ±0.5%, blue ±0.25%, gold ±5%, and silver ±10%.