In Singapore, L1R5 stands for “Level 1, Relevant 5,” which refers to the scoring system used for admission to junior colleges (JCs) and Millennia Institute (MI) after the completion of the Singapore-Cambridge GCE Ordinary Level (O-Level) examinations.

The L1R5 score is calculated by adding up the scores obtained in one language subject (L1) and five relevant subjects (R5), excluding the subjects Mother Tongue Language, Higher Mother Tongue Language, and certain Foundation subjects. The L1 subject is typically English, and the R5 subjects are chosen from a list of subjects approved by the Ministry of Education (MOE).

The MOE determines the list of approved subjects, which may vary over time. As of my knowledge cutoff in September 2021, the list of approved subjects for L1R5 scoring includes:

1. English Language (Compulsory)
2. Mathematics (Compulsory)
3. A Science subject (Physics, Chemistry, Biology)
4. A Humanities subject (History, Geography, Literature in English, Literature in Chinese, Literature in Malay, Literature in Tamil)
5. Another subject (from the list of approved subjects)