Energy Converter
Convert Joule, kWh, calorie, BTU and ft·lbf instantly.
Inputs
J
kWh
cal
BTU
About Energy Units
- The Joule (J) is the SI unit of energy, equal to 1 N·m = 1 kg·m²/s². It is used in physics and engineering for work, heat and electrical energy. The kilowatt-hour (kWh = 3,600,000 J) is the practical unit for electricity billing.
- The calorie (cal) — specifically the international table (IT) calorie = 4.1868 J — is the thermochemical unit. The food calorie (kcal) = 1,000 cal = 4,186.8 J. The BTU (British Thermal Unit, IT) = 1,055.06 J is used for HVAC and heating systems.
- The foot-pound force (ft·lbf) is an imperial energy unit commonly used for impact energy in materials testing (Charpy/Izod impact tests) and for tightening torque in US mechanical standards. 1 ft·lbf = 1.35582 J.
- Quick reference: 1 kWh = 3,600,000 J = 860,421 cal = 3,412 BTU · 1 BTU = 1,055.06 J = 252.16 cal · 1 cal = 4.1868 J.
| 1 单位 | = J | = cal | = BTU |
|---|---|---|---|
| 焦耳(J) | 1 | 0.238846 | 0.000948 |
| 千瓦时(kWh) | 3,600,000 | 860,421 | 3,412.14 |
| 卡路里(cal) | 4.1868 | 1 | 0.003966 |
| 英热单位(BTU) | 1,055.06 | 252.164 | 1 |
| 英尺磅力(ft·lbf) | 1.35582 | 0.323832 | 0.001285 |