Energy Converter

Select energy unit

Input value

Conversion Results

International System of Units (SI)

Joule (J)-

Kilojoule (kJ)-

Nutrition units

Calorie (cal)-

Kilocalorie (kcal)-

Engineering units

British thermal unit (BTU)-

Watt-hour (Wh)-

Kilowatt-hour (kWh)-

Horsepower hour (hph)-

Scientific units

Electronvolt (eV)-

Erg (erg)-

Ton of TNT (t TNT)-

About the Energy Converter

Supported unit systems:

SI: J, kJ
Nutrition: cal, kcal
Engineering: BTU, Wh, kWh, hph
Scientific: eV, erg, t TNT

Common conversions:

1 kJ = 1000 J
1 cal = 4.184 J
1 kcal = 4184 J
1 BTU ≈ 1055.06 J
1 kWh = 3.6 × 10⁶ J
1 eV ≈ 1.602 × 10⁻¹⁹ J

Use cases:

Nutrition: kcal or kJ
Thermal engineering: J or BTU
Electrical energy: Wh or kWh
Physics: J or eV
Energy engineering: J or hph

Note: All conversions follow international standards. Historical definitions may vary; this tool uses current conventions.

Conversion Tips

• When converting between number systems, pay attention to the base of the original value to avoid input errors
• In binary conversion, every four binary digits directly correspond to one hexadecimal digit
• For decimal to binary conversion, use the division by 2 method and read the remainders from bottom to top
• Scientific notation can simplify the representation of very large or very small numbers