Electrical Calculations: Ohm's Law and Circuits Explained
The everyday electrical maths every hobbyist and electrician uses — Ohm's law, power, sizing a resistor, combining resistors, and the basics of current, voltage and safe wiring.
Series Resistor Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Total resistance
600.00
- Number of resistors
- 3
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Series Resistor Calculator
The Series Resistor Calculator works out your total resistance, along with 1 related figure in an instant. Enter resistor values (comma separated, Ω) and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the resistor values (comma separated, Ω).
- Read off your total resistance, together with number of resistors — the calculator updates automatically, with no button to press.
Worked example
For example, with resistor values (comma separated, Ω) of 100, 200, 300, the total resistance is 600.00.
| Resistor values (comma separated, Ω) | 100, 200, 300 |
|---|
| Total resistance | 600.00 |
|---|---|
| Number of resistors | 3 |
Results are estimates for educational use, not professional advice.
Frequently asked questions
Add the resistor values together. Resistors of 100, 200 and 300 Ω in series total 600 Ω.
Current flows through each resistor in turn, so their resistances stack, giving a total larger than any single resistor.
Type the values separated by commas, such as 100, 200, 300. The calculator adds them and counts how many there are.
In series, resistances add and the total rises. In parallel, the combined resistance falls below the smallest resistor.
Related guides
How to Calculate Series Resistor: Formula, Steps & Examples
Learn how to calculate Series Resistor — the formula explained step by step, with worked examples and a free calculator to check your answer.