Resistor Color Code Calculator & Visualizer
Decode 4-band, 5-band, and 6-band resistor color bands with interactive visual preview and tolerance range.
1. Enter your numbers → 2. Check the answer → 3. Read the steps before you trust it
Resistor Value Decoded
Tolerance: ±5%
Step-by-Step Engineering Calculation
- 1Band 1 (Yellow): 4
- 2Band 2 (Violet): 7 → Significant Digits = 47
- 3Band 3 (Red Multiplier): × 100
- 4Band 4 (Gold Tolerance): ±5%
- 5Calculated Resistance: 47 × 100 = 4.70 kΩ (±5%)
- 6Tolerance Range: 4465.00 Ω to 4935.00 Ω
Formula & Theory
Decodes standard EIA-RS-279 electronic resistor color coding bands into nominal resistance, tolerance, and temperature coefficient.
Variable Definitions
- Bands 1-3:
- Digits (Digits (0-9)) – Significant numerical digits
- Multiplier:
- Multiplier (10^n) – Power of 10 multiplier band
- Tolerance:
- Tolerance (±%) – Manufacturing tolerance range
Worked Engineering Example
Standard 4.7kΩ Resistor
4-Band: Yellow (4), Violet (7), Red (×100), Gold (±5%).
- Bands: Yellow, Violet, Red, Gold
Key Assumptions
- •Standard EIA color code specification.
Limitations & Safety Scope
- •High-precision SMD resistors use numerical EIA-96 codes rather than color bands.
Frequently Asked Questions
How do I tell which end of a resistor to read first?
Look for the tolerance band (Gold, Silver, or wider gap): it is placed on the far right. The significant digit bands are grouped together starting from the left.
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Educational & Reference Notice: This calculator provides technical estimates based on standard physical formulas. Actual electrical installation, protective device sizing, and conductor selection must be verified against the applicable electrical code (NEC, IEC, CEC) by a licensed electrician or qualified professional engineer.