How to Read
the Charts

Note: The charts do not display properly in Netscape 4.7 or earlier browsers, because those browsers are not compliant with the current W3C HTML standard.

     

(B) yard

   

foot

3

 

inch

(A) 12

36

U.K., before 12th c – 1963

(C) 2.54
cm

30.48
cm

0.91438348
m (D)

(F) US, 1893-1959

(E)=100/3937
cm

= 1200/3937
cm

= 3600/3937
m

U.S., after 1959; U.K, after 1963

= 2.54
cm

= 30.48
cm

= 0.9144
m

It's easy; just like reading mileage charts on road maps.

Each unit is represented by one column and one row. The column of the smallest unit is on the left. The taller the column, the bigger the unit.

(A) The number in the box tells how many of the row unit are in the column unit. Here, 12 inches in a foot.

(B) The names of the units may be links to pages with more information about that unit.

(C) The bottom rows of the chart, with a white background and green type, contain equivalents to the column's unit in SI units and sometimes also in U. S. customary units. Here, 1 inch is 2.54 centimeters. Some cautions:

(F) Often the same set of ratios between units was used with different values for the units. For example, in this case the size of the yard has changed, but 3 feet in a yard has not. In such cases, for the more important systems, more than one row of equivalences may be provided.

The charts are offered as a way of showing relationships between units, not to provide conversion factors. The conversion information presented in the charts IS NOT EXHAUSTIVE.

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