1. What is a 4-Band Resistor Calculator?

Definition: This calculator determines the resistance value of a 4-band color-coded resistor based on the color bands.

Purpose: It helps electronics enthusiasts, engineers, and students quickly decode resistor values without memorizing the color code.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( R \) — Resistance value (ohms)
• \( band1 \) — First significant digit (first color band)
• \( band2 \) — Second significant digit (second color band)
• \( band3 \) — Multiplier exponent (third color band)

Explanation: The first two bands represent digits, the third is the multiplier (power of ten), and the fourth (not used here) represents tolerance.

3. Importance of Resistor Color Codes

Details: Color coding allows quick identification of resistor values and is standard across electronic components worldwide.

4. Using the Calculator

Tips: Select the colors of each band from the dropdown menus. The calculator will display the resistance value in ohms (Ω).

5. Frequently Asked Questions (FAQ)

Q1: What about the 4th band?
A: The 4th band represents tolerance (not included in this calculation). Gold = ±5%, Silver = ±10%, none = ±20%.

Q2: How do I read resistors with 5 or 6 bands?
A: 5-band resistors have 3 significant digits. 6-band resistors add a temperature coefficient band.

Q3: What if my resistor has gold/silver in first band?
A: Gold/silver are never valid first bands. Check if you're reading the resistor backwards.

Q4: Why do some resistors have different values than calculated?
A: Real resistors have manufacturing tolerances. The actual value may vary within the tolerance range.

Q5: How do I convert ohms to kilo-ohms or mega-ohms?
A: Divide by 1,000 for kilo-ohms or 1,000,000 for mega-ohms (e.g., 4,700Ω = 4.7kΩ, 1,000,000Ω = 1MΩ).