PHP array of tax rates in decimal format by state. Source: http://en.wikipedia.org/wiki/Sales_taxes_in_the_United_States on June 6, 2013

taxes.php

<?php

$taxes = array(
	'AL' => 0.04,
	'AK' => 0.00,
	'AZ' => 0.066,
	'AR' => 0.06,
	'CA' => 0.075,
	'CO' => 0.029,
	'CT' => 0.0635,
	'DE' => 0.00,
	'DC' => 0.06,
	'FL' => 0.06,
	'GA' => 0.04,
	'GU' => 0.04,
	'HI' => 0.04,
	'ID' => 0.06,
	'IL' => 0.0625,
	'IN' => 0.07,
	'IA' => 0.06,
	'KS' => 0.063,
	'KY' => 0.06,
	'LA' => 0.04,
	'ME' => 0.05,
	'MD' => 0.06,
	'MA' => 0.0625,
	'MI' => 0.06,
	'MN' => 0.06875,
	'MS' => 0.07,
	'MO' => 0.04225,
	'MT' => 0.00,
	'NE' => 0.055,
	'NV' => 0.0685,
	'NH' => 0.00,
	'NJ' => 0.07,
	'NM' => 0.05125,
	'NY' => 0.04,
	'NC' => 0.0475,
	'ND' => 0.05,
	'OH' => 0.055,
	'OK' => 0.045,
	'OR' => 0.00,
	'PA' => 0.06,
	'PR' => 0.055,
	'RI' => 0.07,
	'SC' => 0.06,
	'SD' => 0.04,
	'TN' => 0.07,
	'TX' => 0.0625,
	'UT' => 0.047,
	'VT' => 0.06,
	'VA' => 0.05,
	'WA' => 0.065,
	'WV' => 0.06,
	'WI' => 0.05,
	'WY' => 0.04
);