Convert from vara [Spanish] to millimicron

Unit Definition (vara [Spanish])
Vara is an old Spanish and Portuguese unit of length. Varas are a surveying unit that appears in many deeds in the southern United States, and varas were also used in many parts of Latin America. It varied in size at various times and places; the Spanish unit was set at about 835.9 mm in 1801. At some time value of 33 in (838 mm) was adopted in California, and 33 1/3 inches (847 mm) in Texas.

Unit Definition (millimicron)
A unit of metric measurement 1000 millimeters equal one meter, 10 millimeters equal one centimeter, about 25 millimeters is one inch.