1. What is an SMD Resistor Code Calculator?

Definition: This calculator determines the resistance value of surface-mount device (SMD) resistors based on their 3-digit or 4-digit code.

Purpose: It helps electronics engineers, technicians, and hobbyists quickly decode SMD resistor values for circuit design and repair.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( R \) — Resistance value (ohms)
• \( digit1 \) — First significant digit (0-9)
• \( digit2 \) — Second significant digit (0-9)
• \( multiplier \) — Power of ten multiplier (-2 to 9)

Explanation: The first two digits form the significant figures, and the multiplier determines the number of zeros to add.

3. Importance of SMD Resistor Codes

Details: SMD resistors use compact codes because their small size makes traditional color bands impractical. Understanding these codes is essential for modern electronics work.

4. Using the Calculator

Tips: Enter the first two digits (0-9) and the multiplier exponent (-2 to 9). For example, code "103" would be digit1=1, digit2=0, multiplier=3 (10 × 10³ = 10,000Ω).

5. Frequently Asked Questions (FAQ)

Q1: What does a multiplier of 0 mean?
A: A multiplier of 0 means multiply by 1 (10⁰ = 1). For example, "100" means 10 × 1 = 10Ω.

Q2: How are values below 10Ω represented?
A: Use negative multipliers. For example, "1R0" would be digit1=1, digit2=0, multiplier=-1 (10 × 10⁻¹ = 1Ω).

Q3: What about 4-digit codes?
A: For 4-digit codes, the first three digits are significant figures. This calculator handles the more common 3-digit codes.

Q4: How do I identify tolerance?
A: Tolerance isn't shown in the 3-digit code. Standard SMD resistors are typically ±5% (J) or ±1% (F).

Q5: What does "R" mean in codes?
A: "R" represents a decimal point. For example, "2R2" means 2.2Ω.