Energy Conversion Formulas
Complete formulas for converting between different energy units including joules, calories, BTU, kilowatt-hours, and specialized energy measurements.
⚡ Energy Unit Overview
SI/Scientific
Joule (J): Base SI unit
Kilojoule (kJ): 1,000 J
Megajoule (MJ): 1,000,000 J
Electrical
Watt-hour (Wh): Power × time
Kilowatt-hour (kWh): 1,000 Wh
Electron volt (eV): Particle physics
Thermal
Calorie (cal): Food energy
BTU: British Thermal Unit
Therm: Natural gas
Specialized
Foot-pound: Mechanical work
TNT equivalent: Explosives
Quad: National energy
🔄 Basic SI Energy Conversions
Joule Scale Conversions
Joules to Kilojoules
Example: 5,000 J
5,000 J = 5 kJ
Kilojoules to Megajoules
Example: 2,500 kJ
2,500 kJ = 2.5 MJ
Direct J to MJ
Example: 3,600,000 J
3.6 MJ = 1 kWh
Electrical Energy Conversions
Watt-hours to Joules
Example: 2 Wh
2 Wh = 7,200 J
kWh to Joules
Example: 1 kWh
1 kWh = 3.6 MJ
🔥 Thermal Energy Conversions
Calorie Conversions
Calories to Joules
Example: 500 cal
500 cal = 2,092 J
Food Calories (kcal) to kJ
Example: 250 kcal
250 kcal = 1,046 kJ
BTU Conversions
BTU to Joules
Example: 10 BTU
10 BTU = 10,551 J
BTU to kWh
Example: 3,412 BTU
3,412 BTU ≈ 1 kWh
BTU to Calories
Example: 5 BTU
5 BTU = 1,261 cal
🔧 Mechanical Energy Conversions
Foot-Pound Conversions
Foot-pounds to Joules
Example: 100 ft⋅lbf
100 ft⋅lbf = 135.6 J
Foot-pounds to BTU
Example: 778 ft⋅lbf
778 ft⋅lbf = 1 BTU
Kinetic Energy Calculations
Kinetic Energy Formula
Example: 2 kg object, 10 m/s
KE = 100 J
Potential Energy Formula
Example: 5 kg, height 20 m
PE = 980 J
🏭 Large Scale Energy Units
Natural Gas & Fuel Conversions
Therms to Joules
Example: 0.5 therm
0.5 therm = 52.8 MJ
Therms to kWh
Example: 1 therm
1 therm = 29.3 kWh
Nuclear & Particle Physics
Electron Volts to Joules
Example: 1 MeV
1 MeV = 1.6 × 10⁻¹³ J
TNT Equivalent
Example: 1 kg TNT
1 kg TNT = 4.6 MJ
📊 Energy Conversion Reference Table
| Energy Type | Joules (J) | kWh | kcal | BTU |
|---|---|---|---|---|
| 1 Joule | 1 | 2.78 × 10⁻⁷ | 2.39 × 10⁻⁴ | 9.48 × 10⁻⁴ |
| 1 kWh | 3.6 × 10⁶ | 1 | 860 | 3,412 |
| 1 kcal | 4,184 | 1.16 × 10⁻³ | 1 | 3.97 |
| 1 BTU | 1,055 | 2.93 × 10⁻⁴ | 0.252 | 1 |
| 1 ft⋅lbf | 1.36 | 3.77 × 10⁻⁷ | 3.24 × 10⁻⁴ | 1.29 × 10⁻³ |