Quads to Kilojoules (quad to kJ)

1 quad equals 1.055055853×10¹⁵ kilojoules (rounded).

1 quad = 1.055055853×10¹⁵ kilojoules

How to convert quads to kilojoules

To convert quads to kilojoules, multiply the number of quads by 1.055055853×10¹⁵. The factor is rounded to 10 significant digits. To go the other way, multiply kilojoules by 9.478171203×10⁻¹⁶ (rounded).

kilojoules = quads × 1.055055853×10¹⁵

Example: 10 quads = 1.055055853×10¹⁶ kilojoules.

The 'calorie' on food labels is really a kilocalorie. The thermochemical calorie (4.184 J) is used here unless marked IT.

About these units

Quad (quad)

US customaryTraditional unit (still used in some regions)

One quadrillion BTU (about 1.055×10¹⁸ J). Used to quote national and global energy use; US consumption was about 100 quads in 2005.

Energy planners reach for the quad when joules or gallons become unwieldy. One quad is a quadrillion (10 to the 15th power) British thermal units, a figure the US Department of Energy uses for national and world energy budgets. In SI terms it is about 1.055 exajoules, or 1.055 times 10 to the 18th joules.

Which BTU applies changes the last digits. The figure used here, 1.05505585 times 10 to the 18th joules, corresponds to the International Table BTU of roughly 1,055.06 J. The 59 degree Fahrenheit BTU used in American gas pricing would give a value about 0.02 percent smaller, and the Wikipedia article on the quad does not say which BTU it assumes.

For scale, one quad equals about 8 billion US gallons of gasoline or roughly 293 terawatt-hours of electricity. Wikipedia reports world primary energy production of about 638 quads in 2022. In 2005 the US economy used close to 100 quads, so the unit suits country-sized totals rather than anything a household buys.

1 quad = 1.055055853×10¹⁸ joules (approximately).

Sources: Wikipedia: Quad (unit); EIA: British thermal units (Btu); Wikipedia: British thermal unit

Kilojoule (kJ)

Metric (SI)Current unit

1,000 joules. Food labels in many countries give energy in kilojoules.

Most food labels around the world express energy in kilojoules, which is the calorie's long retirement in action. The calorie came out of heat measurement, and the 1948 CGPM resolution stated that the joule should be preferred as the unit of heat. Labels that still show kilocalories alongside kilojoules rely on the thermochemical calorie of exactly 4.184 joules, so one kilocalorie is about 4.184 kJ.

The kilojoule is a convenient size for a body's daily bookkeeping. A person at rest uses about 5,000 kJ, or roughly 1,200 kcal, per day, and the recommended intake for a moderately active woman is given as 2,000 food calories, which is about 8,400 kJ.

Smaller physical comparisons land in the same range. One watt-hour is 3.6 kJ, a British thermal unit is about 1.1 kJ, exploding a gram of TNT releases about 4.2 kJ, and an alkaline AA battery holds about 9 kJ.

1 kilojoule = 1,000 joules (exactly).

Sources: Wikipedia: Kilojoule; Wikipedia: Joule; Wikipedia: Orders of magnitude (energy)

Related conversions

See all energy units.