Should be listed on the driver's door post. You did not list if it is a DX, or LX so I cannot tell you the size. Click the link for more info.
195 65R15
195/65/R15
205/65-15 for Honda Accord 2001 4 door EX with a V6
185/70/R13
The 2014 Honda Accord has a 2.4 L base engine size.
The 2010 Honda Accord has a 2.4 L base engine size.
The 2006 Honda Accord has a 2.4 L base engine size.
The 2005 Honda Accord has a 2.4 L base engine size.
The 2011 Honda Accord has a 2.4 L base engine size.
The 2001 Honda Accord has a 2.3 L base engine size.
The 2009 Honda Accord has a 2.4 L base engine size.
The 2013 Honda Accord has a 2.4 L base engine size.