Resistor Calculator
Calculate resistor values from color codes, determine resistance in series/parallel, and find power dissipation
Color Code to Value
Select the color bands to calculate resistor value
Value to Color Code
Enter resistor value to get color bands
Series & Parallel Calculator
Calculate total resistance for resistors in series and parallel
Separate values with commas
Color Code Chart
Black
Digit: 0 | ×1
Brown
Digit: 1 | ×10 | ±1%
Red
Digit: 2 | ×100 | ±2%
Orange
Digit: 3 | ×1000
Yellow
Digit: 4 | ×10000
Green
Digit: 5 | ×100000 | ±0.5%
Blue
Digit: 6 | ×1000000 | ±0.25%
Violet
Digit: 7 | ×10000000 | ±0.1%
Gray
Digit: 8 | ×100000000 | ±0.05%
White
Digit: 9 | ×1000000000
Gold
×0.1 | ±5%
Silver
×0.01 | ±10%
Formulas
Ohm's Law
V = I × R
P = V × I = I²R = V²/R
Series Resistance
Rtotal = R₁ + R₂ + R₃ + ...
Parallel Resistance
1/Rtotal = 1/R₁ + 1/R₂ + 1/R₃ + ...
Color Code Reading
Value = (Band1 × 10 + Band2) × Multiplier ± Tolerance