# Electrical Circuit Calculation, Power, and Cable Sizing Tools

Compare Ohm's law, resistor and capacitor network math, voltage divider and cable drop calculators, electricity cost tools, and power or energy converters in one focused electrical hub.

> Canonical page: https://elysiatools.com/en/hubs/electrical-circuit-power-and-cable-sizing

- **Category:** calculate

- **Keywords:** electrical circuit calculators, ohms law and resistor network tools, voltage divider and cable voltage drop, electricity cost calculator, power and energy unit conversion, resistor color code calculator, capacitor reactance calculator, electrical sizing workflow

## Overview

This hub is for the back-of-the-envelope and pre-install calculations people do before wiring, prototyping, troubleshooting, or estimating operating cost. It keeps resistor and capacitor math, divider design, cable voltage-drop checks, electricity-cost estimation, and power or energy unit conversion together so users can move from a rough electrical question to a more usable answer without bouncing across unrelated calculators.

## Tools

- Ohm's Law and Power Triangle Calculator: Solve for two unknowns among Voltage, Current, Resistance and Power from any two given values, with visual triangles and AC power-factor support
- Resistor Color Code Calculator: Decode and encode 4-band, 5-band, 6-band, and SMD resistor markings
- Resistor Series / Parallel Calculator: Combine resistors in series, parallel, or an arbitrary +/| expression, with per-resistor voltage and power
- Capacitor Series / Parallel / Reactance Calculator: Combine capacitors in series/parallel, compute reactance Xc and RC time constant, with schematics and a reactance curve
- Voltage Divider Calculator: Calculate divider output voltage, solve for R1 or R2, and evaluate load effects with a circuit diagram
- Cable Voltage Drop Calculator: Compute cable voltage drop from current, length, conductor size (AWG/mm²) and material, for DC, single-phase and three-phase circuits
- Electricity Calculator: Calculate electricity costs based on power consumption and usage time
- Energy Unit Converter: Convert between different energy units (joules, calories, kilowatt-hours, BTU, etc.)
- Watt to KW: Convert watts to kilowatts with configurable decimal precision
- KW to Watt: Convert kilowatts to watts with configurable decimal precision
- Watt to HP: Convert watts to horsepower with configurable decimal precision
- KW to HP: Convert kilowatts to horsepower with configurable decimal precision

## Frequently asked questions

### How is this different from the general measurement and unit conversion hub?

The broader unit-conversion hub is about switching between many measurement systems. This hub is narrower and more workflow-driven: it centers on electrical relationships, component math, cable loss, and the power or energy conversions that support real circuit decisions.

### When should I use voltage divider and voltage drop tools together?

Use the voltage divider calculator when you are intentionally designing a circuit to produce a target output voltage. Use the cable voltage drop calculator when you need to estimate unintended loss across a wire run, branch circuit, or feeder because current, distance, and conductor size change what arrives at the load.

### Why include electricity cost and horsepower conversions next to resistor and capacitor tools?

Real electrical tasks often begin with component or circuit math and end with equipment sizing, motor comparison, or operating-cost questions. Keeping those steps together is useful for DIY builds, maintenance planning, lab exercises, and light industrial troubleshooting.

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