Here's a chart.. Since youre a size 5 in the philippines, youre a 2.5 in the UK...

British 2/ 2.5/ 3/ 3.5/ 4/ 4.5/ 5/ 5.5/ 6/ 6.5/ 7/ 7.5/ 8
American 4.5/ 5/ 5.5/ 6/ 6.5/ 7/ 7.5/ 8/ 8.5/ 9/ 9.5/ 10/ 10.5