Series Resistance Calculator
Add resistances in series. Rtotal = R1 + R2 + ... + Rn. Default list 100, 220, 330 Ω sums to 650 Ω. Informational, not a BOM checker.
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How to sum series resistors
- List each resistance in ohms, separated by commas or spaces.
- Use at least two positive values. Zero-ohm jumpers are not modeled here.
- Read total ohms and the count of resistors parsed.
- For two-resistor voltage split, see the voltage divider page. Nothing is uploaded.
Series resistance
Sum of path resistors
| Rule | Rtotal = R1 + R2 + ... + Rn |
|---|---|
| Current | Same current through each series element |
| Voltage | Drops add around the loop |
| Input | Comma-separated ohms list or R1, R2 fields |
| Default | 100 + 220 + 330 = 650 Ω |
| Approval | Informational. Not a circuit sign-off. |
Series addition rule
Resistors in series share one current path. Their resistances add. The default triple 100, 220, and 330 Ω totals 650 Ω. Power dissipation still depends on current through each part; this page only sums ohms.
Series vs parallel
Parallel resistors combine with reciprocals. Series is the simpler sum. Use the parallel page when branches share the same two nodes.
Not a voltage divider by itself
Two series resistors divide voltage, but this URL only totals ohms. For a split from a known supply, open voltage divider.
From color bands to numbers
Convert band colors to ohms on resistor color, then paste the numeric list here.
Limits
Ideal resistors at one temperature.
The formula runs in this tab. CZNull does not receive the numbers.
Informational only. Not wiring, code, or manufacturer approval. See the disclaimer.