⚡ Energy Conversion Calculator
Translate energy values across electrical, thermal, and mechanical contexts.
Trusted by engineers, scientists, and students who need to compare battery specs, food energy, HVAC loads, or particle energies.
Supports decimals and scientific notation for very large or small energies.
1 Kilowatt-hours (kWh) equals
3,600,000 Joules (J)
Other Units
Kilojoules (kJ)
3,600
Megajoules (MJ)
3.6
Calories (cal)
860,420.65
Kilocalories (kcal)
860.4207
British Thermal Units (BTU)
3,412.1416
Watt-hours (Wh)
1,000
Kilowatt-hours (kWh)
1
Electronvolts (eV)
22,469,432,668,058,746,000,000,000
How to Use This Calculator
Enter the energy amount
Type the value you want to convert—kilowatt-hours, calories, BTU, joules, or electronvolts.
Select source and target units
Switch between electrical (Wh), thermal (cal, BTU), mechanical (J), and particle physics (eV) units.
Review alternate units
Use the quick reference grid to capture other units for datasheets or reports.
Formula
EJ = Value × (joules per source unit)
Converted Value = EJ ÷ (joules per target unit)
Key factors: 1 kWh = 3.6 MJ, 1 kcal = 4,184 J, 1 BTU ≈ 1,055.056 J, 1 eV ≈ 1.602×10⁻¹⁹ J.
Use the formula breakdown to confirm the calculation logic or perform the conversion manually if needed.
Full Description
Energy appears in many guises—from the kilowatt-hours on a utility bill to the calories in nutrition facts or the BTUs used by HVAC technicians. Translating between these units keeps designs consistent and helps you compare technologies on a level playing field.
The converter routes every value through joules, the SI base unit of energy, to maintain precision. That approach supports large industrial values and extremely small particle energies without losing accuracy.
Use it to sanity-check lab measurements, convert battery capacities, estimate heating loads, or communicate findings to colleagues who prefer different units.
Frequently Asked Questions
Why is everything converted through joules?
Joules are the SI base unit for energy. Using joules as the bridge ensures conversions remain consistent across diverse systems.
Does it handle kilocalories (food calories)?
Yes. One kilocalorie (kcal) is the same as one “Calorie” on nutrition labels. The calculator supports both joules and kilocalories.
Can I convert to BTU per hour or other rates?
Rates combine energy and time. Convert the energy portion here, then divide by the time interval using another calculator.
Is electronvolt (eV) support precise enough?
Yes. The calculator uses the CODATA value for 1 eV in joules, which is accurate for physics and semiconductor work.