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Resistor Color Code Calculator Decode resistor values from color bands with visual selector for 4-band and 5-band resistors.

Resistor Color Code Calculator illustration
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Resistor Color Code Calculator

Decode resistor values from color bands with visual selector for 4-band and 5-band resistors.

1

Select Band Type

Choose between 4-band or 5-band resistor.

2

Click Color Bands

Select colors for each band using the visual color picker.

3

Read Resistance

See the decoded resistance value, tolerance, and range.

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What Is Resistor Color Code Calculator?

The Resistor Color Code Calculator decodes the color bands on through-hole resistors to determine their resistance value and tolerance. It supports both 4-band resistors (2 digit bands + multiplier + tolerance) and 5-band resistors (3 digit bands + multiplier + tolerance). The visual interface lets you click on color swatches to select each band, and displays a visual representation of the resistor with your selected colors. The calculator shows the nominal resistance value with appropriate units (Ω, kΩ, MΩ), the tolerance percentage, and the minimum/maximum resistance range.

Why Use Resistor Color Code Calculator?

  • Visual color band selector — no memorization needed
  • Supports both 4-band and 5-band resistors
  • Shows tolerance range (minimum to maximum resistance)
  • Visual resistor display updates in real-time

Common Use Cases

Electronics Hobbyists

Quickly decode resistor values when building circuits.

Education

Learn the resistor color code system interactively.

Repair & Maintenance

Identify resistor values during electronic repair work.

Component Sorting

Verify resistor values when organizing component inventory.

Technical Guide

The resistor color code assigns numeric values to colors: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9. For 4-band: Value = (Band1×10 + Band2) × Multiplier. For 5-band: Value = (Band1×100 + Band2×10 + Band3) × Multiplier. Multiplier colors: Black=×1, Brown=×10, Red=×100, up to White=×10⁹, Gold=×0.1, Silver=×0.01. Tolerance colors: Brown=±1%, Red=±2%, Green=±0.5%, Blue=±0.25%, Violet=±0.1%, Grey=±0.05%, Gold=±5%, Silver=±10%.

Tips & Best Practices

  • 1
    The tolerance band is usually spaced slightly apart from the others
  • 2
    Hold the resistor with the tolerance band on the right to read left-to-right
  • 3
    Gold and silver are only used for multiplier and tolerance bands, never for digits
  • 4
    5-band resistors are typically precision components (1% or better tolerance)

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Frequently Asked Questions

Q How do I tell which end to read from?
The tolerance band (gold, silver, or precision color) is usually slightly separated from the other bands. Read from the opposite end.
Q What is the difference between 4-band and 5-band?
4-band has 2 significant digits (±5-10% tolerance). 5-band has 3 significant digits (±1% or better). 5-band resistors are more precise.
Q What does the tolerance mean?
Tolerance indicates the accuracy. A 1kΩ ±5% resistor can be anywhere from 950Ω to 1050Ω.
Q Are there 6-band resistors?
Yes, 6-band resistors have an additional band for temperature coefficient. This calculator covers the most common 4 and 5-band types.
Q Can I use this for SMD resistors?
No, SMD (surface mount) resistors use a numeric code system (e.g., "472" = 4.7kΩ), not color bands.

About This Tool

Resistor Color Code Calculator is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.