Which end do I start from?
Start at the end farthest from the tolerance band (often gold/silver).
Resistor Color Code Calculator
Translate resistor color bands into resistance value and tolerance for 4-band or 5-band parts.
Decode resistor bands
Select 4-band or 5-band, then choose each band color from the body toward the tolerance band.
About this calculator
How to use Resistor Color Code Calculator, plus the formulas and logic behind the results.
Tool description
The Resistor Color Code Calculator decodes standard 4-band and 5-band color markings into resistance and tolerance.
How to use
- Choose 4-band or 5-band.
- Set each band color in order.
- Select Calculate to view resistance and tolerance.
Formulas & reference
4-band: R = (10×d1 + d2) × multiplier5-band: R = (100×d1 + 10×d2 + d3) × multiplier
Band order
- 4-band: digit, digit, multiplier, tolerance
- 5-band: digit, digit, digit, multiplier, tolerance
- Read from the end opposite the tolerance band
Calculation logic
Digits and multipliers are looked up from standard color tables. 4-band uses two digits plus multiplier; 5-band uses three digits plus multiplier, then a tolerance color.
For 4-band mode, the 3rd select is the multiplier and the 4th is tolerance (5th ignored). Gold/silver appear only where valid.
Resistor Color Code Calculator FAQ
Common questions about this calculator and how to use the results.
What is a 5-band resistor?
It adds a third significant digit for tighter values.
Why is gold a multiplier?
Gold means ×0.1; silver means ×0.01.
What if there is no tolerance band?
Treat tolerance as ±20% (none).
Are 6-band resistors supported?
Not in this version—use the first five bands for value/tolerance.
Does temperature coefficient appear?
Some 6-band parts include TCR; this tool focuses on resistance and tolerance.