Resistor Calculator
Calculate resistance from color codes, series and parallel combinations, and power dissipation.
Your Input
Select a calculation type (color code, series, parallel, or power), enter values or select bands, then click Calculate to see the result and step-by-step solution.
Complete User Guide
What is a Resistor?
A resistor is an electrical component that limits or regulates the flow of electrical current. Resistance is measured in ohms (Ω) and is indicated by colored bands on the resistor body.
How to Use
- Select a calculation type
- Enter the required values or select colors
- Click Calculate to see the result and step-by-step solution
- Use Reset to clear and hide results
Calculation Types
- Color Code: Decode resistance from color bands
- Series Resistance: Calculate total resistance in series
- Parallel Resistance: Calculate total resistance in parallel
- Power Dissipation: Calculate power from voltage and resistance
Resistor Color Code
- 4-Band: 2 digits, multiplier, tolerance
- 5-Band: 3 digits, multiplier, tolerance
- 6-Band: 3 digits, multiplier, tolerance, temp coeff
Formulas
Series:
R_total = R1 + R2 + R3 + ...
Parallel:
1/R_total = 1/R1 + 1/R2 + 1/R3 + ...
Power:
P = V² / R
Color Values
Black=0, Brown=1, Red=2, Orange=3, Yellow=4
Green=5, Blue=6, Violet=7, Gray=8, White=9
Gold=×0.1, Silver=×0.01
Important Notes
- Resistance values must be greater than zero
- Voltage must be non-negative
- Color bands are read from left to right
- Tolerance indicates the accuracy range
Common Applications
- Circuit design and analysis
- Resistor identification
- Component selection
- Power rating calculations
- Electronics education