Series and parallel resistor calculator
Find the total of resistors wired in series or in parallel, or make a value you do not have out of two you do.
Series 3.2 kΩ · Parallel 688 Ω
- Series
- 1 kΩ + 2.2 kΩ = 3.2 kΩ
- Parallel
- (1 kΩ × 2.2 kΩ) ÷ (1 kΩ + 2.2 kΩ) = 688 Ω
The formulas
| Wiring | Total |
|---|---|
| Series | R = R1 + R2 + R3 + … |
| Parallel | 1/R = 1/R1 + 1/R2 + 1/R3 + … |
| Two in parallel | R = (R1 × R2) ÷ (R1 + R2) |
Series and parallel
In series the resistors go end to end and the same current flows through all of them; the total is the sum of the values: 220 Ω and 220 Ω in series make 440 Ω. In parallel both ends of the resistors are joined; the current shares itself out and the total is below even the smallest one. Two equal resistors in parallel halve the value: two 1 kΩ make 500 Ω. Without a 150 Ω, put two 300 Ω in parallel, or 100 Ω and 47 Ω in series. To read a resistor's value from its colors: the resistor color code
In the app, tick off every wire, match the parts to your inventory and pick up where you left off.
