I earned my BA in the USA and my MPA in the UK. Reversing your question (aka 'what GPA equivalent is a 2:1 in the UK), I have found that most employers equate a 2:1 to somewhere between a 3.3 and a 3.7 on a 4.0 scale, with most top consultancies opting for 3.5. Others follow the latin honour scheme used by some American universities (e.g. magna cum laude = 2.1).That said, I would note that any large US/multinational firm is familiar with the UK education system and can handle this conversion without your intervention . I would recommend against trying to convert the grade yourself.