1. What is a Resistor Value Calculator SMD?

Definition: This calculator determines the resistance value of SMD (Surface Mount Device) resistors based on their 3-digit code.

Purpose: It helps electronics engineers, technicians, and hobbyists quickly decode SMD resistor markings.

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

Explanation: The first two digits form the significant figures, which are multiplied by 10 raised to the power of the third digit.

3. Importance of SMD Resistor Codes

Details: SMD resistors are marked with a numerical code since their small size makes color bands impractical. Understanding these codes is essential for circuit design and repair.

4. Using the Calculator

Tips: Enter the three-digit code from your SMD resistor (first two digits as numbers, third digit as the exponent). For example, "103" would be 10 × 10³ = 10kΩ.

5. Frequently Asked Questions (FAQ)

Q1: What if my resistor has more than 3 digits?
A: 4-digit codes work similarly but with three significant digits (e.g., "1002" = 100 × 10² = 10kΩ).

Q2: How do I read EIA-96 codes?
A: EIA-96 uses two digits and a letter, requiring a different decoding table not covered by this calculator.

Q3: What's the smallest SMD resistor size?
A: Common sizes range from 0402 (0.04" × 0.02") down to 01005 (0.016" × 0.008") for ultra-compact designs.

Q4: How accurate are SMD resistors?
A: Standard SMD resistors are typically ±1% or ±5% tolerance, with precision versions available at ±0.1%.

Q5: What does "R" mean in SMD codes?
A: "R" represents a decimal point (e.g., "4R7" = 4.7Ω, "R33" = 0.33Ω).