PHP: show a number to 2 decimal places  What's the correct way to round a PHP string to 2 decimal places? $number = "520"; // It's a string from a DB $formatted_number = round_to_2dp($number); echo $formatted_number; Output is "520.00"; How function round_to_2dp() definition should be? Best Answer :   can use number_format(): return number_format((float)$number, 2, '.', ''); Example: $foo = "105"; echo number_format((float)$foo, 2, '.', ''); // Outputs -> 105.00 This function returns a string.