Resistor Calculator

Identify resistor values and tolerances from color bands or encode resistance into standard color codes.

How to use this calculator

1. Select 4/5 band.
2. Pick colors.
3. Read Ohms and tolerance.

Formula & method

IEC 60062 Color Code

R = (D1 D2) × Multiplier ± Tol

Standard resistor code.

Example

Brown Black Red Gold = 1,000 Ω ± 5%.

Key insights

• Gold = 5%, Silver = 10%.

How to interpret your result

Resistance

Ohms rating.

Frequently asked questions

Which side first?

Start opposite tolerance band.

Related calculators

• Ohm's Law Calculator — Calculate Voltage, Current, Resistance, or Power (V = I × R, P = V × I).
• Voltage Drop Calculator — Calculate wire voltage drop and percentage loss according to NEC standards.

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