How do I calculate resistors in parallel?

Add the reciprocals and invert: 1/Rtotal = 1/R₁ + 1/R₂ + … For two resistors, Rtotal = R₁R₂/(R₁+R₂).

What is the total of two 100 Ω resistors in parallel?

50 Ω — two equal resistors in parallel give half the value.

Series adds up to a larger total; parallel always gives less than the smallest resistor in the group.

Enter your resistor values (in ohms), choose series or parallel, and get the total resistance.

Resistor values (Ω) — separate with commas, spaces or new lines

Connection

Resistors in series add up:

R_total = R₁ + R₂ + R₃ + …

Resistors in parallel combine as the reciprocal of the sum of reciprocals:

1 / R_total = 1/R₁ + 1/R₂ + 1/R₃ + …

The parallel total is always smaller than the smallest resistor in the group, while the series total is the simple sum.

How do I calculate resistors in parallel?: Add the reciprocals and invert: 1/Rtotal = 1/R₁ + 1/R₂ + … For two resistors, Rtotal = R₁R₂/(R₁+R₂).
What is the total of two 100 Ω resistors in parallel?: 50 Ω — two equal resistors in parallel give half the value.
Series or parallel — which is bigger?: Series adds up to a larger total; parallel always gives less than the smallest resistor in the group.

Total capacitance of any combination.

Output voltage from two resistors.

Split a current between two parallel resistors.

V, I, R, P from any two.