Resistor Color Code Calculator
Decode resistor color bands to find resistance and tolerance. Enter your 4 or 5 color bands — get resistance, tolerance range, and nearest standard value.
Enter your values above to see the results.
Tips & Notes
- ✓Read bands from the end closest to the terminal lead (the end with the gold/silver tolerance band is usually the right side — read from the other end). When in doubt, the tolerance band is always gold (±5%) or silver (±10%) for 4-band resistors.
- ✓Memory aid for color digit sequence — Bad Boys Race Our Young Girls But Violet Generally Wins: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Gray=8, White=9.
- ✓Gold multiplier band = ×0.1 (gives values below 10 Ω, e.g., Brown-Black-Gold = 1.0 Ω). Silver multiplier = ×0.01 (e.g., Brown-Black-Silver = 0.1 Ω). Not to be confused with tolerance gold/silver.
- ✓5-band resistors have three significant digit bands — they are typically 1% metal film types. The reading direction matters more: find the tolerance band (brown=±1%, red=±2%, green=±0.5%) and read from the opposite end.
- ✓Resistor markings on SMD (surface mount) components use a numeric code instead of color bands. 3-digit: first two digits + number of zeros. 4-digit: first three digits + zeros. "473" = 47,000 Ω = 47 kΩ. "4702" = 47,000 Ω = 47 kΩ.
Common Mistakes
- ✗Reading bands in the wrong direction — always start from the end away from the tolerance band. On 4-band resistors, the gold or silver tolerance band is at the right end when reading left to right.
- ✗Confusing the multiplier band with a digit band — in a 4-band resistor, band 3 is the multiplier (power of 10), not a third digit. Red as band 3 means ×100, not the digit 2.
- ✗Misreading brown and orange, or blue and violet — these color pairs are commonly confused under poor lighting. Use a multimeter to verify resistance when color identification is uncertain.
- ✗Forgetting that gold and silver serve double duty — as a multiplier (band 3), gold = ×0.1 and silver = ×0.01. As a tolerance band (band 4/5), gold = ±5% and silver = ±10%. Context determines meaning.
- ✗Assuming all 5-band resistors are 1% — some 5-band resistors have ±2% (red tolerance) or ±0.5% (green tolerance). Read all five bands carefully and use a multimeter for verification when precision matters.
Resistor Color Code Calculator Overview
Resistor color codes are the first practical skill in electronics — every physical resistor in your hand needs to be identified, and reading the color bands accurately is faster than measuring with a multimeter for common values.
4-band color code formula:
R = (D1 × 10 + D2) × 10^(Multiplier value) | ±Tolerance% from last band
EX: Orange-Orange-Brown-Gold → D1=3, D2=3, Multiplier=1 (×10), Tol=±5% → R = (3×10+3)×10 = 330 Ω ±5% → Range: 313.5 to 346.5 Ω5-band color code formula:
R = (D1 × 100 + D2 × 10 + D3) × 10^(Multiplier value) | ±Tolerance% from last band
EX: Brown-Green-Black-Brown-Brown → D1=1, D2=5, D3=0, Mult=1 (×10), Tol=±1% → R = 150 × 10 = 1,500 Ω = 1.5 kΩ ±1% → Range: 1,485 to 1,515 ΩComplete color code chart:
| Color | Digit Value | Multiplier | Tolerance | Temp Coef (ppm/°C) |
|---|---|---|---|---|
| Black | 0 | ×1 | — | — |
| Brown | 1 | ×10 | ±1% | 100 |
| Red | 2 | ×100 | ±2% | 50 |
| Orange | 3 | ×1,000 | — | 15 |
| Yellow | 4 | ×10,000 | — | 25 |
| Green | 5 | ×100,000 | ±0.5% | — |
| Blue | 6 | ×1,000,000 | ±0.25% | — |
| Violet | 7 | ×10,000,000 | ±0.1% | — |
| Gray | 8 | — | ±0.05% | — |
| White | 9 | — | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
| Code | Value | Code | Value | Code | Value |
|---|---|---|---|---|---|
| 100 | 10 Ω | 472 | 4.7 kΩ | 104 | 100 kΩ |
| 220 | 22 Ω | 103 | 10 kΩ | 474 | 470 kΩ |
| 471 | 470 Ω | 223 | 22 kΩ | 105 | 1 MΩ |
| 102 | 1 kΩ | 473 | 47 kΩ | 000 | 0 Ω (jumper) |
Frequently Asked Questions
Identify the tolerance band (gold or silver) at one end — read from the opposite end. Band 1: first significant digit (the color value 0-9). Band 2: second significant digit (0-9). Band 3: multiplier (power of 10 — Red=×100, Orange=×1000, Yellow=×10000). Band 4: tolerance (Gold=±5%, Silver=±10%). Example: Yellow-Violet-Red-Gold → 4-7-×100-±5% = 4,700 Ω = 4.7 kΩ ±5% (range: 4,465 to 4,935 Ω). Brown-Black-Orange-Gold → 1-0-×1000-±5% = 10,000 Ω = 10 kΩ ±5%.
5-band resistors are typically 1% precision metal film types. The tolerance band is brown (±1%), red (±2%), or occasionally green (±0.5%). Read from the end away from the tolerance band. Band 1: first digit. Band 2: second digit. Band 3: third digit. Band 4: multiplier. Band 5: tolerance. Example: Brown-Green-Black-Black-Brown → 1-5-0-×1-±1% = 150 Ω ±1% (range: 148.5 to 151.5 Ω). Red-Red-Black-Red-Brown → 2-2-0-×100-±1% = 22,000 Ω = 22 kΩ ±1%.
Tolerance indicates the acceptable variation from the marked value. Gold (±5%): carbon film resistors, general-purpose circuits. Silver (±10%): older resistors, non-critical applications. Brown (±1%): metal film, precision circuits, voltage dividers. Red (±2%): moderate precision. Green (±0.5%): high precision. For most digital circuits, ±5% (gold) is adequate. For analog circuits with gain stages, current mirrors, or precision voltage references, use ±1% or better. A 10 kΩ ±5% resistor may be anywhere from 9,500 to 10,500 Ω.
Surface mount resistors use a numeric code printed on the top. 3-digit code: first two digits are significant digits, third is the number of zeros. "472" = 47 × 100 = 4,700 Ω = 4.7 kΩ. "103" = 10 × 1,000 = 10,000 Ω = 10 kΩ. "000" = 0 Ω (jumper). 4-digit code (for 1% precision): first three digits, fourth is zeros. "4702" = 470 × 100 = 47,000 Ω = 47 kΩ. "1001" = 100 × 10 = 1,000 Ω = 1 kΩ. "R" notation: "4R7" = 4.7 Ω, "47R" = 47 Ω (R replaces the decimal point).
Set the multimeter to resistance (Ω) mode, selecting a range above the expected resistance. Disconnect the resistor from any circuit — measuring in-circuit gives incorrect readings because parallel components affect the measurement. Touch the probes to the resistor leads; polarity doesn't matter for resistance measurement. Compare the reading to the color code value. Acceptable reading: within the tolerance range (±5% for gold, ±1% for brown). If outside tolerance, the resistor may be damaged, out of specification, or you may be reading the color code incorrectly. Body temperature affects resistance slightly — hold probes, not the resistor.
The most frequently used resistors in electronics: 10 Ω (current sensing), 100 Ω (signal termination, current limiting), 470 Ω (LED current limiting with 5 V), 1 kΩ (pull-up/pull-down, general purpose), 4.7 kΩ (pull-up for I2C, logic signals), 10 kΩ (most common single value — voltage dividers, pull-ups, bias resistors), 22 kΩ and 47 kΩ (feedback networks, filters), 100 kΩ (high-impedance nodes, op-amp inputs), 1 MΩ (very high impedance, ADC input protection). Having 10 Ω through 1 MΩ in the E12 series covers 95% of circuit needs.