Quadratic Equation Solver (ax² + bx + c = 0)
About Resistance Calculator
The Electrical Resistance & Impedance ($\Omega$) Calculator computes electrical resistance using Ohm's Law ($R = V/I = V^2/P = P/I^2$), Series Circuits ($R_{eq} = \sum R_i$), Parallel Circuits ($1/R_{eq} = \sum 1/R_i$), 4/5/6-band Resistor Color Codes, and Conductor Resistivity ($R = \rho L / A$).
How to Use Resistance Calculator
Step 1
Select Color Code Mode or Ohm's Law / Network Mode.
Step 2
Select color bands from dropdowns or enter known Voltage/Current/Power.
Step 3
Review computed resistance in Ohms ($\Omega$), Kilohms (k$\Omega$), and Megohms (M$\Omega$).
Step 4
Click "Copy Resistance Value".
Practical Use Cases for Resistance Calculator
Resistor Color Code Decoding & EIA Standard Values (E12/E24/E96)
Decode 4-band, 5-band, and 6-band colored ceramic resistor bands into exact Ohmic resistance and tolerance percentage.
Parallel Resistor Network Equivalent Impedance Synthesis
Synthesize custom non-standard resistance values by calculating equivalent resistance for parallel and series resistor combinations.
Input & Output Examples
Decoding 4-Band Resistor: Yellow - Violet - Orange - Gold
Bands: `Yellow (4)`, `Violet (7)`, `Orange (×1k)`, `Gold (±5%)`
Resistance: `47,000 Ω (47 kΩ)` | Tolerance: `±5% (44.65 kΩ to 49.35 kΩ)` | Standard EIA Code: `E24 Series`
Key Features & Performance
- ✓Resistor Color Band Decoder & Encoder (4-band, 5-band, 6-band with temperature coefficient ppm/K).
- ✓Series & Parallel Network Calculator: instantly solves parallel combinations with exact fractional mathematics.
- ✓Conductor Resistance & Skin Effect: computes wire resistance from material resistivity ($\rho$), length ($L$), and gauge ($A$).
- ✓100% Client-Side electrical engine.
- ✓1-Click Copy resistance values.
Key Terminology & Definitions
Electrical Resistance ($R$)
The opposition to the flow of electric current in a conductor, measured in Ohms ($\Omega$, where $1\ \Omega = 1\text{ V}/\text{A}$).
Temperature Coefficient of Resistance (TCR)
The relative change of resistance per degree of temperature change, expressed in parts per million per Kelvin (ppm/K).