Grade 3 is an E in a GCSE.
1 = C
2 = D
3 = E
If you took an 'O' level the equivalency to a GCSE is:
A = A
B = B
C = C
1 = C
2 = D
3 = E
If you took an 'O' level the equivalency to a GCSE is:
A = A
B = B
C = C