Calculators for Energy Used in the United States
- Measuring energy in food — food calories versus energy calories
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 3½ 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: |
|
|---|---|
British thermal unit (Btu) |
1.0 |
Millions of Btu |
1.0E+06 Btu |
Therm |
1.0E+05 Btu |
Billions of Btu |
1.0E+09 Btu |
Quad |
1.0E+15 Btu |
Calorie |
1.0 Calorie |
Kilocalorie |
1.0E+03 Calories |
Food calorie |
1.0E+03 Calories |
Thermie |
1.0E+05 Calories |
Teracalorie |
1.0E+12 Calories |
Megajoule |
1.0E+06 Joule |
Joule |
1.0 Joule |
Gigajoule |
1.0E+09 Joules |
1.0E+12 Joules |
|
Watthour |
1.0 |
Kilowatthour (kWh) |
1.0E+03 watthour |
Megawatthour (mWh) |
1.0E+06 watthour |
Gigawatthour (gWh) |
1.0E+09 watthour |
Terawatthour (tWh) |
1.0E+12 watthour |