Common electrical units:
- Power: watt (W), kilowatt (kW)
- Energy: joule (J), kilowatt-hour (kWh)
- Voltage: volt (V), kilovolt (kV)
- Current: ampere (A), milliampere (mA)
- Resistance: ohm (Ω), kiloohm (kΩ)
Key relationships:
- P (W) = V (V) × I (A)
- V (V) = I (A) × R (Ω)
- E (kWh) = P (kW) × t (h)
- 1 hp = 746 W
- 1 kW = 1000 W
Early Development:
Electrical units were established in the 19th century by pioneering scientists like Ampère, Volta, Ohm, and Watt. The International System of Units (SI) formalized these standards to ensure global consistency in measurement.
Modern Standards:
The electrical units we use today were standardized by the International Electrotechnical Commission (IEC) and are maintained by national standards institutes like NIST (USA) and NPL (UK) to ensure precision and uniformity.
Practical Units:
Many practical electrical units like the kilowatt-hour (kWh) emerged from the need to measure electricity consumption for billing purposes, becoming essential in everyday life with the widespread adoption of electrical power.
Power measurements for:
- Appliance consumption ratings
- Generator capacity
- Motor specifications
- Equipment selection
Energy measurements for:
- Utility billing (kWh)
- Battery capacity (Wh)
- Energy efficiency analysis
- Renewable energy production
Circuit calculations for:
- Wiring size determination
- Circuit breaker selection
- Protection device coordination
- Voltage drop calculations
Electricity Unit Conversion Calculator
Conversion Result
Use the converter above to calculate different values and units
What are Electrical Units?
Electrical units are standardized measurements used to quantify various aspects of electricity. These include fundamental units like volts (voltage), amperes (current), ohms (resistance), watts (power), and derived units like kilowatt-hours (energy).
These units are interrelated through fundamental laws like Ohm's Law (V = IR) and power equations (P = VI). Understanding these relationships is crucial for electrical engineering, electronics, power system design, and everyday applications like household energy consumption.
Learn more from NIST or International Electrotechnical Commission (IEC).
Common Electrical Conversions
| Power/Energy | Equivalent | Voltage | Current |
|---|---|---|---|
| 1 kilowatt (kW) | 1,000 watts (W) | 230V | 4.35A |
| 1 horsepower (hp) | 746 watts (W) | 120V | 6.22A |
| 1 kilowatt-hour (kWh) | 3.6 megajoules (MJ) | - | - |
| 1 BTU/hr | 0.293 watts (W) | - | - |
| 1 megawatt (MW) | 1,000 kilowatts (kW) | 11kV | 90.9A |
Ohm's Law Relationships
| Voltage (V) | Current (A) | Resistance (Ω) | Power (W) |
|---|---|---|---|
| 120V | 10A | 12Ω | 1,200W |
| 230V | 5A | 46Ω | 1,150W |
| 12V | 2A | 6Ω | 24W |
Practical Applications of Electrical Conversions
Home Energy Management
- Converting watts to kilowatt-hours for estimating electricity bills
- Comparing energy consumption of different appliances
- Calculating savings from energy-efficient devices
- Sizing home solar installations based on energy needs
Electrical Engineering
- Calculating proper wire gauge based on current requirements
- Determining appropriate circuit breaker ratings
- Converting between voltage levels for transformer design
- Designing proper grounding systems
Electronics & DIY Projects
- Calculating power requirements for electronic components
- Converting between milliamps and amps for battery capacity
- Determining resistor values for LED circuits
- Sizing power supplies for custom builds
Renewable Energy
- Converting watts to kilowatt-hours for solar panel production estimates
- Calculating battery storage requirements in amp-hours
- Sizing inverters based on power needs
- Estimating payback periods based on energy production
Industrial Applications
- Converting between horsepower and kilowatts for motor specifications
- Calculating power factor correction capacitor values
- Estimating energy consumption costs for equipment
- Determining appropriate transformer sizing
Educational Resource
This educational video from Engineering Mindset explains the fundamental concepts of electrical power and energy, with clear explanations of watts, kilowatts, and kilowatt-hours, and how these units relate to each other.
Electrical Conversion Resources
Get our comprehensive electrical conversion chart showing power, energy, voltage, and current equivalents for quick reference during electrical calculations.
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Electricity Conversion FAQs
Find answers to common questions about electrical measurements and power conversions.