Convert from attometer to fathom [ancient]

Unit Definition (attometer)
An Attometer (or attometre) is equal to one quintillionth of a meter, or sometimes denoted as 10e-18 meters. The origin of the prefix is atten, the word for 18 in Danish and Norwegian.

Unit Definition (fathom [ancient])
A fathom is a unit of measure equal to 2 yards or 6 feet, or 1.8288 metres. The name of the unit derives from the Old English word fæthm meaning 'outstretched arms' which was the original definition of the unit's measure.