HTML code of this table:

<table cellspacing="0" cellpadding="16" rules="none" id="idTable"> <col width="100"> <col width="200"> <col width="300"> <tr> <td style="background-color: red; color: white;">1st cell</td> <td style="background-color: green; color: white;">2nd cell</td> <td style="background-color: blue; color: white;">3rd cell</td> </tr> </table>

The table width (offsetWidth) is

• 696px wide in MSIE 6 SP1, MSIE 6 SP2 and MSIE 7 beta 3 build 5450.4
• 600px wide in Mozilla 1.8b2 build 2005051205, in Firefox 1.5, Firefox 2.x, Firefox 3, Seamonkey 2.0a1pre rv: 1.9pre build 2008041401, Internet Explorer 8 beta 1
• 600px wide in Netscape 7.2 rv: 1.7.2 build 20040804
• 600px wide in Opera 6.06 build 1145
• 696px wide in Opera 7.23, Opera 8.0 build 7561, Opera 9.0 build 8031, Opera 9.27, Opera 9.50a1 build 9500, Opera 9.50 build 9903
• 696px wide in Safari 2.0.4 and in Konqueror 3.5.8
• 600px wide in Safari 3.0.2

Table's offsetWidth

Expected results: the table offsetWidth should be precisely 600px.

A <col>'s width is equal to a table's cellspacing + 2 * cellborder width + 2 * cellpadding width + cell content's width in the border-collapse: separate model.

Reference: "In this [automatic table layout] algorithm (which generally requires no more than two passes), the table's width is given by the width of its columns (and intervening borders)." coming from CSS 2.1, Section 17.5.2.2