Free Resistor Color Codes Value Calculator: Decode Band Colors Instantly

Resistor Color Codes Value Calculator for 4, 5, and 6‑Band Resistors

A Resistor Color Codes Value Calculator decodes the colored bands printed on resistors into numeric resistance, tolerance, and (when present) temperature coefficient. It saves time and reduces errors compared with manual lookup.

How it works

• Each colored band maps to a digit, multiplier, tolerance, or temperature coefficient per standard color code charts.
• 4‑band: band 1 = first significant digit, band 2 = second digit, band 3 = multiplier, band 4 = tolerance.
• 5‑band: band 1–3 = first three significant digits, band 4 = multiplier, band 5 = tolerance — used for higher‑precision resistors.
• 6‑band: same as 5‑band plus band 6 = temperature coefficient (ppm/°C), used in precision or temperature‑sensitive applications.

Typical outputs

• Resistance value in ohms with SI suffixes (Ω, kΩ, MΩ) and calculated numeric value (e.g., 4.7 kΩ = 4700 Ω).
• Tolerance as a percentage (e.g., ±1%), and minimum/maximum resistance range based on tolerance.
• For 6‑band resistors, temperature coefficient in ppm/°C and how resistance shifts with temperature.

Common color-to-value mapping (summary)

• Black = 0, Brown = 1, Red = 2, Orange = 3, Yellow = 4, Green = 5, Blue = 6, Violet = 7, Gray = 8, White = 9
• Multipliers: same colors represent 10^n (e.g., Red = ×100)
• Tolerance: Gold = ±5%, Silver = ±10%, Brown = ±1%, Red = ±2%, Green = ±0.5%, Blue = ±0.25%, Violet = ±0.1%, Gray = ±0.05%
• Temperature coefficient (ppm/°C): Brown = 100, Red = 50, Orange = 15, Yellow = 25, Blue = 10, Violet = 5 (varies by standard)

Using a calculator

1. Select the band count (4, 5, or 6).
2. Choose the color for each band.
3. Read the displayed resistance, tolerance, and (if applicable) temperature coefficient and min/max range.
4. Optionally convert units (Ω/kΩ/MΩ) or copy the numeric value for circuit calculations.

Practical tips

• Verify band order — the tolerance band is usually separated slightly from the others.
• For faded bands, compare under good lighting or use a magnifier; when uncertain, measure with a multimeter.
• Use 5‑ or 6‑band decoding for precision resistors (tight tolerances or critical temperature behavior).

If you want, I can provide a small calculator script (JavaScript or Python) that decodes 4/5/6‑band resistors.