Resistor Calculator
Determine resistance using 4, 5, and 6 color band codes, series/parallel circuit configurations, and wire conductor properties.
Resistor Color Code Calculator
Series & Parallel Resistance Calculator
Enter individual resistor values separated by commas (e.g., 10, 220, 1000).
Conductor Wire Resistance Calculator
How to Read Resistor Color Codes
Resistor color bands provide a quick visual standard to identify resistance values, tolerance limits, and temperature coefficients. Standard axial resistors use 4, 5, or 6 color bands:
- 4-Band Resistors: The first two bands represent significant digits, the third band is the decimal multiplier, and the fourth band indicates tolerance.
- 5-Band Resistors: Higher precision resistors where the first three bands represent significant digits, the fourth is the multiplier, and the fifth is tolerance.
- 6-Band Resistors: Similar to 5-band resistors, with an additional sixth band specifying the Temperature Coefficient in PPM/K.
Frequently Asked Questions
Read the bands from left to right. The 1st and 2nd bands give the significant numbers, the 3rd band represents the multiplier (10ⁿ), and the 4th band gives the tolerance level (e.g., Gold = ±5%).
A 4-band resistor has 2 digit bands. A 5-band resistor adds a 3rd digit band for higher precision. A 6-band resistor adds a Temperature Coefficient band to show resistance variance with temperature changes.
In a series circuit, resistances add directly ($R_{total} = R_1 + R_2 + \dots$). In a parallel circuit, total resistance decreases according to reciprocal addition ($1/R_{total} = 1/R_1 + 1/R_2 + \dots$).
Resistance is directly proportional to conductor length and inversely proportional to its cross-sectional area. Longer wires increase resistance, while thicker wires lower it.
Gold indicates a tolerance of ±5%, while Silver indicates ±10%. A tighter tolerance means the actual manufactured resistance value is closer to its rated value.