Buying baby clothes is a lot like playing the lottery; you hedge your bets on a number, and hope it&#39;s the right one.<p>But it doesn&#39;t have to be that way. While it&#39;s true that babies grow really fast, it is possible to buy clothes for them that will fit - at least for now. Use our size and age chart to help determine what size you should buy.</p><p><b>Remember: when in doubt, make your purchase based on weight and height rather than age!</b> It&#39;s always safe to go one size bigger, except in the case of baby sleepwear.</p><p><b>US Size and Age Chart</b></p><table cellpadding="1" cellspacing="1" border="1" width="425"><tr><td><b>Age/Size</b></td><td><b>Weight</b></td><td><b>Length</b></td><td><b>Bootie/Shoe Size</b></td><td><b>Sock Size</b></td></tr><tr><td>Newborn</td><td>Up to 7 lbs</td><td>Up to 17&#34;</td><td>N/A</td><td>N/A</td></tr><tr><td>Up to 3 Months</td><td>7-12 lbs</td><td>17-23&#34;</td><td>3</td><td>Up to 6 Months</td></tr><tr><td>3-6 Months</td><td>12-17 lbs</td><td>23-27&#34;</td><td>4</td><td>Up to 6 Months</td></tr><tr><td>6-12 Months</td><td>17-22 lbs</td><td>27-29&#34;</td><td>5</td><td>6-12 Months</td></tr><tr><td>12-18 Months</td><td>22-27 lbs</td><td>29-31&#34;</td><td>6</td><td>12-24 Months</td></tr><tr><td>18-24 Months</td><td>27-30 lbs</td><td>31-33&#34;</td><td>7</td><td>12-24 Months</td></tr></table>