Resistors in Series Calculator
⚡ Electricity & magnetism. Use the Resistors in series formula to find total resistance, r₁, r₂, r₃: pick the value you want, type the others, and the answer updates as you go.
Total resistance30 Ω
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Total resistance | Ω |
| R₁ | Ω |
| R₂ | Ω |
| R₃ | Ω |
Worked example
Find the total resistance when R₁ = 10 Ω, R₂ = 20 Ω, R₃ = 0 Ω.
Using R = R1 + R2 + R3: Total resistance = 30 Ω.
Frequently asked questions
What is the formula for Resistors in series?
R = R1 + R2 + R3.
What do the letters stand for, and what units are used?
Total resistance in Ω, R₁ in Ω, R₂ in Ω, R₃ in Ω.
How do you calculate total resistance?
Put the values into R = R1 + R2 + R3. For example, with R₁ = 10 Ω, R₂ = 20 Ω, R₃ = 0 Ω, total resistance = 30 Ω.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (total resistance, r₁, r₂, r₃) and fill in the others: it rearranges the formula for you.
