SMD Resistor Value Calculator | Decode 3 & 4 Digit SMD Codes Online

Instantly decode SMD resistor codes. Use this free calculator to convert 3-digit, 4-digit and R-notation SMD codes into resistance (Ω, kΩ, MΩ).

SMD Resistor Calculator

Resistance Value:

0 Ω

Selected Code:

Intro

Surface-mount resistors (SMD) often show a tiny code — 3 digits, 4 digits, or an “R” notation — instead of a printed ohm symbol. This post explains how those codes map to resistance values and provides a ready-to-paste SMD Resistor Value Calculator you can embed in your Blogger post or gadget.

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How SMD codes work (simple guide)

• 3-digit code (common): First two digits = significant figures, 3rd digit = power of ten multiplier (10^n).
  Example: 472 → 47 × 10^2 = 4700 Ω = 4.7 kΩ.

• 4-digit code: First three digits = significant figures, 4th digit = multiplier.
  Example: 1001 → 100 × 10^1 = 1000 Ω = 1 kΩ.

• R notation: 4R7 means 4.7 Ω (the R denotes the decimal point). 0R22 → 0.22 Ω.

• EIA-96 / 2- or 3-character codes: (not covered by this simple tool). EIA-96 requires a lookup table — see FAQ below.

Example conversions (so you know it's working)

• 472 → 47 × 10^2 = 4700 Ω = 4.7 kΩ

• 104 → 100 × 10^4 = 1,000,000 Ω = 1 MΩ (4-digit example)

• 4R7 → 4.7 Ω

• 10 → 10 Ω (treated as direct value)

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FAQ

Q: Does this decode EIA-96 codes?
A: No — the EIA-96 scheme uses a two-digit code plus a letter multiplier and needs a lookup table. If you need EIA-96 support I can add a full decoder (requires a table of 96 code→value mappings).

Q: Where to place this code in Blogger?
A: Recommended: open your post in HTML view and paste the block where you want the calculator to appear. Or go to Layout → Add a Gadget → HTML/JavaScript and paste it as a gadget (title optional).

Q: Will this slow my page?
A: No — it's lightweight vanilla JS and minimal HTML/CSS. It doesn't load external libraries.