VoltDrop.app Feedback

The voltage drop calculator that explains itself. No signup, no guessing.

🧮 Power Calculator

Volts, amps, watts, kW and kVA — enter what you know, get the rest. DC, single-phase, and three-phase.

DC: batteries, solar, vehicles, LED strips.

volts

Three-phase: use the line-to-line voltage (e.g. 208, 480).

watts

Tip: 1 kW = 1,000 W. A label that says "1.5 kW" is 1500 watts.

0–1

How efficiently the load uses current. Heaters and simple loads: 1.0. Motors and fluorescent lighting: often 0.8–0.9. If unsure, leave 1.0.

Watts vs kW vs kVA — the 30-second version

Watts (W) is real usable power; 1 kW = 1,000 W. kVA is the "apparent" power the wiring actually has to carry. For heaters and simple loads they're equal. For motors and electronics, some current sloshes back and forth without doing useful work — that's why kVA can be higher than kW, and the ratio between them is the power factor.

The formulas we use

DC: watts = volts × amps. Single-phase AC: watts = volts × amps × power factor. Three-phase AC: watts = √3 (1.732) × line-to-line volts × amps × power factor. Every result shows its math — open "How we calculated this."

Sizing wire for this load? Take the amps from here straight into the Wire Size and Ampacity Check tools.