3 Band Resistor Color Code Guide & Calculator
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).
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 Guide & Calculator
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.