Series Resistor Calculator

A series resistor circuit places components end to end along one continuous current path. Because charge has no branch to follow, the same current passes through every resistor. The equivalent resistance is therefore the simple sum of the individual values: R total = R1 + R2 + R3. This calculator adds the three entered resistances, applies Ohm's law to the complete circuit, and then determines the voltage consumed by each resistor. Once total resistance is known, circuit current follows from I = V / R total. Voltage across each component is then Vn = I x Rn. These drops should add back to the source voltage, which is Kirchhoff's voltage law and a useful check on a hand calculation. A larger resistor receives a proportionally larger voltage drop, while equal resistors divide the source equally. The displayed current is in amperes, resistance is in ohms, and voltage drops are in volts. Series networks appear in current-limiting designs, sensor chains, bias circuits, LED circuits, and voltage dividers. A practical voltage divider often uses only two resistors, but the same method extends to three or any larger number. The calculator keeps three values visible so students and designers can quickly explore how changing one part redistributes voltage without changing the single-path nature of the circuit. Real resistors have tolerance and power limits. A nominal 100-ohm part with a five-percent tolerance may not measure exactly 100 ohms, so physical results can differ slightly from an ideal calculation. Power dissipated by a resistor is P = I squared x R, and the selected component should have a rating comfortably above that value. Excessive power can heat the resistor, alter its resistance, or damage it. Use positive DC values for a straightforward ideal model. The same resistance addition works for instantaneous resistive AC circuits, but reactive components require impedance and phase calculations instead. Wire resistance and source internal resistance can also matter in high-current or low-resistance systems. For ordinary design checks, classroom exercises, and breadboard planning, this calculator gives a fast and transparent result with each intermediate quantity shown.