Electronics
Series/Parallel Resistors
Paste any number of resistor values to see the equivalent resistance if they were wired in series or in parallel.
Paste resistor values and see the equivalent resistance for series and parallel networks.
Equivalent resistance
Series: R_eq = ΣRᵢ Parallel: 1/R_eq = Σ(1/Rᵢ)
Series resistances simply add together. Parallel resistances add as reciprocals—the more branches you add, the lower the net resistance becomes.
How to use
- Type resistor values separated by commas, spaces, or new lines.
- Keep everything in ohms (use kilo/mega-ohms converted to ohms if needed).
- Read the total for both wiring styles and confirm the number of branches processed.
Example
Input: 10, 22, 47, 100
Output: Series ≈ 179 Ω, Parallel ≈ 5.3 Ω
Student-friendly breakdown
This walkthrough emphasizes the most searched ideas for Series/Parallel Resistors: Series/Parallel Resistors. Start with the formula above, then follow the guided steps to double-check your work. For quick revision, highlight the givens, plug into the equation, and finish by verifying your units.
Need more support? Use the links below to open the long-form guide, browse additional examples, or hop into adjacent calculators within the same topic — each one is a quick way to double-check your work or handle a related question without starting from scratch.
Deep dive & study plan
Series/Parallel Resistors: Equivalent resistance calculator plus branch count at a glance. It's built around resistors, series, parallel, so you can go from a raw question to a checked answer without switching tools.
The math behind it: Series resistances simply add together. Parallel resistances add as reciprocals—the more branches you add, the lower the net resistance becomes. The core relationship is Series: R_eq = ΣRᵢ Parallel: 1/R_eq = Σ(1/Rᵢ), shown above the calculator so you can see exactly how your inputs turn into the result.
To use it well: (1) Type resistor values separated by commas, spaces, or new lines. (2) Keep everything in ohms (use kilo/mega-ohms converted to ohms if needed). (3) Read the total for both wiring styles and confirm the number of branches processed. Keep your units consistent as you go, and re-run a case you already know the answer to — it's the fastest way to catch a typo before it throws off a result you're relying on.
Worked example: entering 10, 22, 47, 100 returns Series ≈ 179 Ω, Parallel ≈ 5.3 Ω. Try swapping in your own numbers next, especially a case you're unsure about, before you use this for something that matters.
Quick retention checklist
- Speak the formula aloud (or annotate it) so the relationships stick.
- Write each step in your own words and compare with the numbered list above.
- Swap in new numbers for the Example to make sure the calculator (and your logic) handles edge cases.
- Check at least one related calculator below — it's the fastest way to confirm your numbers still line up from a different angle.
FAQ & notes
Can I mix kilo-ohms and ohms?
Convert everything to ohms before entering the list. Example: 4.7 kΩ becomes 4700.
What happens with a zero-ohm jumper?
Parallel resistance collapses to zero if any branch is 0 Ω. The calculator reports the result as undefined in that case.
What formula does the Series/Parallel Resistors use?
Series resistances simply add together. Parallel resistances add as reciprocals—the more branches you add, the lower the net resistance becomes.
How do I use the Series/Parallel Resistors?
Type resistor values separated by commas, spaces, or new lines. Keep everything in ohms (use kilo/mega-ohms converted to ohms if needed). Read the total for both wiring styles and confirm the number of branches processed.