Instantly calculate resistance, current, voltage, and power in series, parallel, and mixed electrical circuits using our free interactive tools.
Calculate voltage, current, resistance, or power using Ohm's Law (V = IR, P = VI).
Calculate total resistance of resistors connected in series (Rtotal = R1 + R2 + ... + Rn).
Calculate total resistance of resistors connected in parallel (1/Rtotal = 1/R1 + 1/R2 + ... + 1/Rn).
Calculate total resistance of mixed series and parallel resistor networks.
Calculate output voltage of a voltage divider circuit (Vout = Vin × R2 / (R1 + R2)).
Calculate current through parallel branches (I1 = Itotal × R2 / (R1 + R2)).
Calculate electrical power using P = VI, P = I²R, or P = V²/R.
Calculate total capacitance for capacitors in series or parallel.
Calculate total inductance for inductors in series or parallel.
Compute total impedance in RLC AC circuits (Z = √(R² + (XL - XC)²)).
Determine the time constant τ = RC for charging/discharging capacitors.
Compute τ = L/R for RL circuits.
| Calculator | Input Values | Result |
|---|---|---|
| Ohm's Law | V=12V, R=100Ω | I=120mA, P=1.44W |
| Series Resistor | R1=100Ω, R2=220Ω | Rtotal=320Ω |
| Parallel Resistor | R1=100Ω, R2=100Ω | Rtotal=50Ω |
| Voltage Divider | Vin=12V, R1=1kΩ, R2=2kΩ | Vout=8V |
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | 100 | |
| Brown | 1 | 101 | ±1% |
| Red | 2 | 102 | ±2% |
| Orange | 3 | 103 | |
| Yellow | 4 | 104 | |
| Green | 5 | 105 | ±0.5% |
| Blue | 6 | 106 | ±0.25% |
| Violet | 7 | 107 | ±0.1% |
| Gray | 8 | 108 | ±0.05% |
| White | 9 | 109 | |
| Gold | 10-1 | ±5% | |
| Silver | 10-2 | ±10% |
| Type | R1 (Ω) | R2 (Ω) | V (Volts) | Result |
|---|---|---|---|---|
| Series | 100 | 220 | 9V | Total R = 320Ω, I = 28.1 mA |
| Parallel | 100 | 220 | 9V | Total R ≈ 68.8Ω, I = 130.8 mA |
| Voltage Divider | 1kΩ | 2kΩ | 12V | Vout = 8V |
| Current Divider | 100Ω | 220Ω | 100mA | I1 = 68.75mA, I2 = 31.25mA |
| Power | 120Ω | 12V | P = 1.2W | |
| Capacitor Parallel | 10μF | 22μF | Ctotal = 32μF | |
| Inductor Series | 10mH | 22mH | Ltotal = 32mH |