As we’ve just explored, PHP has some built in functions for converting numbers from or to binary, hex, or octal with respect to decimal numbers. This function, base_convert(), will convert a number from any base to any base.

That’s not entirely true. It only works with bases 2-36 inclusive, but that should be enough for the common stuff.

$bin = '10100010';
$oct = '624';
$dec = '1985';
$hex = 'C477DF';
 
$res = base_convert($bin, 2, 10);  // 162
$res = base_convert($bin, 2, 16);  // a2
$res = base_convert($oct, 8, 10);  // 404
$res = base_convert($oct, 8, 2);   // 110010100
$res = base_convert($dec, 10, 2);  // 11111000001
$res = base_convert($dec, 10, 16); // 7c1
$res = base_convert($hex, 16, 10); // 12875743
$res = base_convert($hex, 16, 8);  // 61073737
 
$res = base_convert('17', 22, 3);     // 1002
$res = base_convert('OU812', 36, 12); // 11b80032
See the manual entry for base_convert()
Originally posted 2009-03-19