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Energy Converter

33+ units

Convert between joules, calories, BTU, kilowatt hours, and other energy units with professional precision and instant results.

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Energy Converter

33 units

Convert between joules, calories, BTU, and other energy units with precision.

Understanding Energy Measurement Systems

SI Units (International System)

The standard scientific energy measurement system

  • • Joule (J) - Base unit of energy
  • • Kilojoule (kJ) - 1,000 joules
  • • Megajoule (MJ) - 1,000,000 joules
  • • Gigajoule (GJ) - 1,000,000,000 joules

Electrical Units

Energy consumption and generation

  • • Watt Hour (Wh) - Basic electrical energy
  • • Kilowatt Hour (kWh) - Household electricity
  • • Megawatt Hour (MWh) - Industrial scale
  • • Gigawatt Hour (GWh) - Power plant scale

Thermal Units

Heat energy and thermal systems

  • • Calorie (cal) - Heat to warm 1g water 1°C
  • • Kilocalorie (kcal) - Food energy
  • • BTU - British Thermal Unit
  • • Therm - Natural gas energy

Atomic & Nuclear Units

Particle physics and nuclear energy

  • • Electron Volt (eV) - Atomic scale energy
  • • Kiloelectron Volt (keV) - X-ray energy
  • • Megaelectron Volt (MeV) - Nuclear reactions
  • • Gigaelectron Volt (GeV) - Particle accelerators

Essential Conversion Factors

Common Conversions

1 kWh3.6 MJ
1 BTU1,055 J
1 kcal4,184 J
1 ft⋅lbf1.356 J

Quick Approximations

1 kWh ≈860 kcal
1 BTU ≈0.25 kcal
1 therm ≈29.3 kWh
1 hp⋅h ≈0.746 kWh

Scientific Units

1 eV1.602×10⁻¹⁹ J
1 erg10⁻⁷ J
1 Ry13.6 eV
1 Ha27.2 eV

Professional Applications

Electrical Engineering

  • • Power system design and analysis
  • • Energy storage system sizing
  • • Electrical load calculations
  • • Motor and generator specifications
  • • Power quality assessments

HVAC Systems

  • • Heating and cooling load calculations
  • • Energy efficiency ratings
  • • Thermal comfort analysis
  • • Building energy modeling
  • • Heat pump performance evaluation

Renewable Energy

  • • Solar panel energy output
  • • Wind turbine performance
  • • Battery storage capacity
  • • Grid integration studies
  • • Energy payback calculations

Nutrition & Food Science

  • • Caloric content analysis
  • • Metabolic rate calculations
  • • Food labeling compliance
  • • Dietary planning and assessment
  • • Sports nutrition optimization

Physics & Research

  • • Particle physics experiments
  • • Nuclear reaction calculations
  • • Spectroscopy analysis
  • • Materials science research
  • • Quantum mechanics studies

Automotive Industry

  • • Fuel efficiency calculations
  • • Electric vehicle range
  • • Engine performance analysis
  • • Emissions testing
  • • Hybrid system optimization

Common Energy Examples

Everyday Energy

AA Battery5 Wh
Smartphone Battery15 Wh
Laptop Battery50 Wh
Daily Food Intake2000 kcal

Transportation

Gallon of Gasoline33.7 kWh
Tesla Model S Battery100 kWh
Jet Fuel (1 gallon)38.6 kWh
Natural Gas (1 therm)29.3 kWh

Household & Industrial

Average Home (daily)30 kWh
Electric Water Heater4 kWh/day
Nuclear Power Plant24 GWh/day
Lightning Strike1-5 GJ
Frequently Asked Questions

What's the difference between calories and Calories?

A calorie (cal) is the energy to heat 1g of water by 1°C. A Calorie (Cal) or kilocalorie (kcal) equals 1,000 calories and is used in nutrition.

How do I convert between electrical and thermal energy?

Use the conversion: 1 kWh = 3.6 MJ = 860 kcal = 3,412 BTU. These conversions assume 100% efficiency.

What energy unit should I use for scientific calculations?

Use joules (J) for most scientific work. For atomic physics, use electron volts (eV). For large-scale energy, use megajoules (MJ) or gigajoules (GJ).

How accurate are these energy conversions?

Our conversions use internationally recognized constants and are accurate to 8+ decimal places, suitable for professional and scientific applications.

About Professional Unit Conversion

Unit conversion is the mathematical process of changing measurements from one unit system to another while maintaining equivalent values. PrecisionConvert specializes in providing precise, reliable unit conversions essential for engineering, construction, scientific research, and everyday applications.

Our advanced conversion algorithms utilize internationally recognized standards from NIST (National Institute of Standards and Technology) and ISO (International Organization for Standardization) to ensure 99.9% accuracy. Whether you're converting millimeters to inches for precision manufacturing, celsius to fahrenheit for weather analysis, or kilograms to pounds for shipping calculations, PrecisionConvert delivers the precision professionals demand.

PrecisionConvert supports over 300 unit types across 20+ categories, making it the comprehensive solution for engineers, architects, designers, students, and anyone requiring accurate measurement conversions. Our real-time calculations eliminate errors and save valuable time on critical projects.

From metric to imperial conversions and specialized engineering units, PrecisionConvert bridges measurement systems used worldwide, ensuring seamless collaboration across international projects and industries.

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