Column Width calculation in Excel

Hi
1)
What is the unit of measurement for width in cols jaxb element in sheet.xml. Is it in twips/emu/points?
<cols>
<col min="1" max="1" width="9.718784877232142" customWidth="true"/>
</cols>
2)
Secondly i get coloumn width= 51.02 points. How is it converted to fetch 9.71?
3)
Any idea on column width conversions in Excel?
1)
What is the unit of measurement for width in cols jaxb element in sheet.xml. Is it in twips/emu/points?
<cols>
<col min="1" max="1" width="9.718784877232142" customWidth="true"/>
</cols>
2)
Secondly i get coloumn width= 51.02 points. How is it converted to fetch 9.71?
3)
Any idea on column width conversions in Excel?