Resistor Color Code Calculator
Decode resistor color bands to find resistance value and tolerance. Supports 4-band and 5-band resistors with all standard EIA colors.
Resistance
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Tolerance —
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Resistance
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Tolerance —
Min Value —
Max Value —
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Resistance
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Tolerance (%) —
Min Value —
Max Value —
Current at V —
Power Dissipation —
Nearest E24 Value —
How to Use This Calculator
- Select the number of bands (4 or 5).
- Select each color band from the dropdown menus left to right.
- The resistance value and tolerance range are shown immediately.
Formula
4-band: (B1×10 + B2) × Multiplier ± Tolerance%
5-band: (B1×100 + B2×10 + B3) × Multiplier ± Tolerance%
Example
Example: Yellow–Violet–Red–Gold → (4×10+7) × 100 = 4,700 Ω ±5% (standard 4.7 kΩ resistor).
Frequently Asked Questions
- For a standard 4-band resistor: bands 1 and 2 are significant digits (0–9 each), band 3 is the multiplier (power of 10), and band 4 is tolerance. Read from the end closest to the first band (the band nearest one lead). Multiply the 2-digit number formed by bands 1 and 2 by the multiplier of band 3. Example: Yellow (4) – Violet (7) – Red (×100) – Gold (±5%) = 47 × 100 = 4,700 Ω ±5% = 4.7 kΩ. The mnemonic "Bad Beer Rots Our Young Guts But Vodka Goes Well" helps remember Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White (0–9).
- Black represents the digit 0 on resistor color bands and also serves as the multiplier ×1 (10⁰ = 1). So a resistor with Black as the multiplier band has the base value of the first two digits with no multiplication. For example, Yellow–Violet–Black–Gold = 47 × 1 = 47 Ω ±5%. Black is also occasionally used as a tolerance band on very old resistors to indicate ±20%, though in modern coding only gold and silver are used for tolerance on 4-band resistors. In 5-band resistors, black in the multiplier position still means ×1.
- The gold band on a resistor indicates a tolerance of ±5%, meaning the actual resistance can be anywhere from 5% below to 5% above the nominal value. For a 1,000 Ω (1 kΩ) resistor with gold tolerance, the actual value is between 950 Ω and 1,050 Ω. Silver tolerance = ±10%. No band = ±20% (very old or very cheap resistors). Brown = ±1%. Red = ±2%. Green = ±0.5%. Blue = ±0.25%. Violet = ±0.1%. For most circuit applications, ±5% (gold) is sufficient. Precision circuits requiring tight tolerances use ±1% or better (brown band).
- Five-band resistors are precision components where three digits are used for the significant value (rather than two in a 4-band resistor), giving 1000 possible values instead of 100. The bands are: digit 1, digit 2, digit 3, multiplier, tolerance. Example: Brown (1) – Black (0) – Black (0) – Red (×100) – Brown (±1%) = 100 × 100 = 10,000 Ω = 10 kΩ ±1%. These are common in precision instrumentation, medical devices, and audio circuits. The 5-band resistor often has the body color tilted toward brown or maroon, and the tolerance band may be a distinctly different width than the others.
- The 10 digit colors (0–9) are: Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (7), Gray (8), White (9). For multiplier bands, Gold = ×0.1 (for values below 10 Ω) and Silver = ×0.01 are also used. For tolerance bands: Gold ±5%, Silver ±10%, Brown ±1%, Red ±2%, Green ±0.5%, Blue ±0.25%, Violet ±0.1%. The EIA (Electronic Industries Alliance) standardized these color codes globally. This calculator decodes both 4-band and 5-band resistors from any combination of these colors.