R
Resistance Calculator
The total resistance of resistors in series or parallel, or a wire’s resistance from its material, length and thickness.
Result…
How it's calculated
Series: R = R₁ + R₂ + … Parallel: 1/R = 1/R₁ + 1/R₂ + … Wire: R = ρ × L ÷ A
Resistors in series add up; in parallel the current has several paths, so the total falls below the smallest one. Two equal resistors in parallel give half of one. A wire’s resistance grows with its length and falls with its cross-section, scaled by the material’s resistivity.
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