Convert from dalton to gigagram

Unit Definition (dalton)
The dalton is an alternate name for the unified atomic mass unit (u or amu). The dalton is often used in microbiology and biochemistry to state the masses of large organic molecules; these measurements are typically in kilodaltons (kDa). It seems necessary to have such a unit, since "kilo-amu" would be such a clumsy name. The SI accepts the dalton as an alternate name for the unified atomic mass unit and specifies Da as its proper symbol. The unit honors the English chemist John Dalton (1766-1844), who proposed the atomic theory of matter in 1803.

Unit Definition (gigagram)
An SI unit of mass equal to 10E9 grams, one million kilograms, or 1 kilotonne (1000 metric tons). This unit is used in scientific contexts, such as the measurement of atmospheric emissions. One gigagram equals about 2.2046 million pounds or 1102.3 U.S. (short) tons.