I will caveat Axel's response here and say this is not always an ideal approach. I did this initially, but for whatever reason, most courses like Economics/Law at Russell Group uni's had relatively drastically higher requirements in my own country's A-level equivalents. For example, in England approx. 20% of A-level students in a given year will receive AAA or above grades in their A-levels. When I was looking at courses with AAB-esque requirements for UK applicants (so we are talking at least top 20% of test takers if 20% receive AAA) the equivalent grades you needed in my country would place you in the top 3% of results. I believe this is because they poorly interpreted the grade equivalents (e.g. comparing an A-level 'A' as like-for-like with another, when it is not the case).
What I would do instead is:
1. Explicitly state what percentile you came in nationally in your country's exams, if you can
2. Calculate your UCAS Tariff points - these can be a bit more accurate
3. Find the reverse - what are A-level entry requirements for universities in your own country? (This also helped me corroborate my claim, as my grades were rated as A*A*A* equivalent on webpages for UK applicants by universities in my country)
