### 15.3 Field Width ¶

By default, the output value is left aligned and shown with the minimum width necessary for the specified (or default) precision. If a field width greater than this is specified, the value shown is right aligned, and padded on the left with enough spaces to provide the specified field width. A width specification is typically used with fixed-point decimal to have columns of numbers align at the decimal point; this arguably is less useful with `units` than with long columnar output, but it may nonetheless assist in quickly assessing the relative magnitudes of results. For example, with the format ‘`%12.6f`’,

    You have: km
    You want: in
            * 39370.078740
            /     0.000025

    You have: km
    You want: rod
            *   198.838782
            /     0.005029

    You have: km
    You want: furlong
            *     4.970970
            /     0.201168