3 Band Resistor Color Code Calculator & Guide
The 3-band resistor system is primarily encountered in vintage electronics, guitar amplifiers, and legacy tube radios. It consists of two significant digit bands and one multiplier band, with no tolerance band (implied ±20% tolerance).
How to Read 3 Band Resistor Color Code Calculator & Guide
Read the two significant digit bands followed by the multiplier stripe from left to right (standardized default tolerance is ±20% with no 4th stripe):
| Band Position | Function | Permitted Values |
|---|---|---|
| Band 1 | 1st Significant Digit | 0 to 9 (Black to White) |
| Band 2 | 2nd Significant Digit | 0 to 9 (Black to White) |
| Band 3 | Multiplier (Power of 10) | 10⁻² (Silver) to 10⁹ (White) |
- 1.Identify the Gap: Resistors feature a wider physical gap separating the multiplier/digits from the tolerance band.
- 2.Identify Tolerance Metal: A Gold or Silver band is never a first digit; it always marks the tolerance band on the right.
- 3.Combine Mantissa & Multiply: Group the digit numbers together (e.g. Red 2 + Red 2 = 22) and multiply by the multiplier color (Orange ×1,000 = 22 kΩ).
Resistor Color Code Calculator
Select band count and click colors below to calculate resistance and tolerance.
Select Band Colors
Click any swatch to change value
Reverse Resistor Color Code Lookup
Enter resistance value in Ohms (Ω) to determine the exact color bands.
Enter Target Resistance
Live ValidationCommon Questions About 3 Band Resistor Color Code Calculator & Guide
What is the tolerance of a 3-band resistor?▼
Under the IEC 60062 standard, any resistor lacking a fourth tolerance stripe has an assumed default tolerance of ±20%.
Complete Resistor Color Code Chart
View the full 12-color lookup matrix covering significant figures 0–9, multipliers from 0.01 to 1G, and tolerance bands from ±0.05% to ±20%. Includes searchable values and instant CSV export.
How to Read & Calculate Resistor Bands
Learn step-by-step reading rules, standard E-series decade values (E12, E24, E96), memory mnemonics, and surface-mount (SMD) 3-digit and EIA-96 code conversion formulas.
Popular Resistor Color Code Guides & Calculators
Jump directly to pre-calculated stripe guides for common standard resistances or explore individual band systems.