Calculators for energy used in the United States
- Natural gas
- Crude oil
- Diesel fuel and heating oil
- Measuring energy in food—food calories versus energy calories
- Scientific notation explained—E+10
Note: Btu is British thermal units.
Measuring energy in food
Food calories are a measure of energy in food. One food calorie is equal to 1,000 calories, or 1 kilocalorie. For example, the energy in a 300-food calorie ice cream cone is about the same as the amount of electricity required to light a 100-watt incandescent light bulb for 3.5 hours.
Scientific notation explained
Scientific notation is a short-hand way of writing a number that has a lot of digits. For example, the number 525,000,000 could be written as 5.25E+08. The +08 indicates the decimal should be moved eight places to the right. A negative number after the E means the decimal should be moved a certain number of places to the left. For example, 5.25E-03 is the same as 0.00525.
|Common energy units||Scientific notation|
|British thermal unit (Btu)||1.0|
|millions of Btu||1.0E+06 Btu|
|billions of Btu||1.0E+09 Btu|
|food calorie||1.0E+03 calories|
|kilowatthour (kWh)||1.0E+03 Watthour|
|megawatthour (mWh)||1.0E+06 Watthour|
|gigawatthour (gWh)||1.0E+09 Watthour|
|terawatthour (tWh)||1.0E+12 Watthour|