Use this calculator when resistors are connected end-to-end and the total resistance is the direct sum of the values you enter.
Inputs
The strongest pages in the library pair the live calculator with a topic guide and, where it helps, a printable reference you can reuse offline.
Use this page when the same current flows through each resistor and the components are connected in one series path.
The main result is the total equivalent resistance. The supporting value lists the resistor values used so the total stays easy to audit.
A 100 ohm resistor, a 220 ohm resistor, and a 330 ohm resistor in series give a total of 650 ohms.
This page assumes simple resistors in series. It does not model tolerance stacking, temperature change, or frequency-dependent impedance.
Combine resistor values in parallel to find the equivalent resistance seen across the network.
Use the Resistor Divider Calculator for practical circuit and electronics work involving resistor divider.
Solve for voltage, current, or resistance from any two values and validate all three when you already have a full set of measurements.
Calculate the voltage dropped across a resistance from the current and resistance values you enter.