Series and Parallel Resistor Calculator
Equivalent resistance of two resistors connected in series and in parallel.
Results
Total resistance
690.000000
Ω
The other way round
149.855072
Ω
In series
690.000000
Ω
In parallel
149.855072
Ω
Number · value · share of the sum
1 470 68.12
2 220 31.88
Components
2
Smallest
220.000000
Ω
Largest
470.000000
Ω
What this tool does
In series, resistances simply add. In parallel, the combination is always smaller than the smaller of the two, which is the quick sanity check: if your parallel answer is larger than either resistor, the formula was applied upside down.
Formula
in series: R = R₁ + R₂ + … · in parallel: 1/R = 1/R₁ + 1/R₂ + …
Variables
| Symbol | Meaning | Unit |
|---|---|---|
values | The resistances, one per line or separated by commas | — |
arrangement | How they are connected | — |
rs | Total resistance | Ω |
rp | The other way round | Ω |
RS | In series | Ω |
RP | In parallel | Ω |
TB | Number · value · share of the sum | — |
NC | Components | — |
MN | Smallest | Ω |
MX | Largest | Ω |
Worked example
- The resistances, one per line or separated by commas470, 220
- How they are connectedseries
- Total resistance690.000000 Ω
- The other way round149.855072 Ω
- In series690.000000 Ω
- In parallel149.855072 Ω
- Number · value · share of the sum1 470 68.12 2 220 31.88
- Components2
- Smallest220.000000 Ω
- Largest470.000000 Ω
Limitations
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.