Resistors in Parallel Calculator
⚡ Electricity & magnetism. Use the Resistors in parallel formula to find total resistance, r₁, r₂: pick the value you want, type the others, and the answer updates as you go.
Total resistance6.6667 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 |
Worked example
Find the total resistance when R₁ = 10 Ω, R₂ = 20 Ω.
Using 1/R = 1/R1 + 1/R2: Total resistance = 6.6667 Ω.
Frequently asked questions
What is the formula for Resistors in parallel?
1/R = 1/R1 + 1/R2.
What do the letters stand for, and what units are used?
Total resistance in Ω, R₁ in Ω, R₂ in Ω.
How do you calculate total resistance?
Put the values into 1/R = 1/R1 + 1/R2. For example, with R₁ = 10 Ω, R₂ = 20 Ω, total resistance = 6.6667 Ω.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (total resistance, r₁, r₂) and fill in the others: it rearranges the formula for you.
