This tool helps you determine the resistance value of a resistor based on its color bands. Simply select the colors of each band and the calculator will show you the corresponding resistance value in ohms.
4-Band Resistor Calculator
Standard resistor with tolerance up to ±5%. Most common type.
Band Types
4-Band Resistors: Standard precision (±5% or ±10%), value = (first digit × 10 + second digit) × multiplier ±tolerance
5-Band Resistors: High precision (±1% or better), value = (first digit × 100 + second digit × 10 + third digit) × multiplier ±tolerance
6-Band Resistors: Ultra precision with temperature stability, same as 5-band plus temperature coefficient
Color Code Reference
Black: 0 (×1 Ω)
Brown: 1 (×10 Ω)
Red: 2 (×100 Ω)
Orange: 3 (×1 kΩ)
Yellow: 4 (×10 kΩ)
Green: 5 (×100 kΩ)
Blue: 6 (×1 MΩ)
Violet: 7 (×10 MΩ)
Gray: 8 (×100 MΩ)
White: 9 (×1 GΩ)
Gold: ×0.1 Ω
Silver: ×0.01 Ω
Tolerance Values (Precision)
Brown: ±1% (Military/Industrial)
Red: ±2% (Precision)
Orange: ±3% (Precision)
Yellow: ±4% (Precision)
Green: ±0.5% (Ultra-precision)
Blue: ±0.25% (Ultra-precision)
Violet: ±0.1% (Laboratory grade)
Gray: ±0.05% (Laboratory grade)
Gold: ±5% (Commercial)
Silver: ±10% (Consumer)
Temperature Coefficient (TC)
Brown: 100 ppm/°C (±0.01%/°C)
Red: 50 ppm/°C (±0.005%/°C)
Orange: 15 ppm/°C (±0.0015%/°C)
Yellow: 25 ppm/°C (±0.0025%/°C)
Blue: 10 ppm/°C (±0.001%/°C)
Violet: 5 ppm/°C (±0.0005%/°C)
Note: ppm = parts per million. Lower TC values indicate better temperature stability.
Practical Examples
4-Band: Brown-Black-Red-Gold = 1.0 × 100 = 100Ω ±5% (Common in signal termination)
5-Band: Red-Violet-Green-Brown-Brown = 275 × 10 = 2.75kΩ ±1% (Typical in precision voltage dividers)
