The International English Language Testing System, or IELTS, is an international standardized test of English language proficiency for non-native English language speakers. It is jointly managed by the British Council, IDP: IELTS Australia and Cambridge Assessment English, and was established in 1989. Wikipedia

Score / grade validity: 24 Months.
Score / grade range: 0 to 9, in 0.5 band increments.
Annual number of test takers: Over 3.5 million in 2018.

Scores / grades used by: More than 10,000 colleges, agencies and other institutions in over 140 countries

Knowledge / skills tested: Listening, reading,