O-Level L1R5 and L1R4 Calculator

What an O-Level aggregate actually is

Every O-Level grade carries a number of points, and the number is already sitting inside the grade. A1 is 1 point, B3 is 3 points, C6 is 6 points, and so on down to F9 at 9 points. An aggregate is just a handful of those point values added together, which is why a lower aggregate is the better one. That trips up a lot of parents the first time they see it.

What makes it more than simple addition is that not every subject counts, and the ones that do have to fit particular slots. L1 is the first language slot and can only be filled by English Language or Higher Mother Tongue, whichever is stronger. The R slots are for the relevant subjects, and some of them are reserved for particular subject groups.

L1R5, the six-subject aggregate

L1R5 is the aggregate junior college admission runs on today. It adds up six subjects: the first language, then five relevant subjects. Three of those five have to satisfy a subject group rule. MOE puts it as two Mathematics or Science subjects and one Humanities subject, or the other way round, two Humanities and one Mathematics or Science. The last two slots go to the next best-scoring subjects, whatever they are.

The best possible L1R5 is 6, which is six A1s. MOE publishes a gross L1R5 of 20 or better as the bar for JC admission through the Joint Admissions Exercise.

L1R4, the five-subject aggregate

L1R4 counts one subject fewer. Millennia Institute already admits on it, and from the 2028 posting exercise junior college admission moves to it as well. The slots are spelled out one by one: R1 is the best Humanities subject, R2 is the best Mathematics or Science subject, R3 is the best of any Humanities, Mathematics or Science subject, and R4 is the best remaining subject of any kind.

The best possible L1R4 is 5. MOE publishes a gross L1R4 of 16 or better for JC admission and 20 or better for Millennia Institute. Note that the JC bar tightens from 20 to 16 when the change happens, because one fewer subject is being added up.

Gross aggregate and net aggregate

The gross aggregate is the plain sum of the slot points. The net aggregate is the gross with bonus points taken off. MOE awards bonus points for things like co-curricular activities, Higher Mother Tongue and school affiliation, capped at 3 points, with a further 2 for students selected for a Language Elective Programme at a JC.

The eligibility figures MOE publishes are stated against the gross aggregate, so bonus points do not buy your way past the bar. What they change is where you sit in the posting queue once you are eligible.

The grade points

SEAB counts A1 to C6 as subject passes. D7, E8 and F9 still carry points into an aggregate if they end up in a slot, which is why a weak sixth subject can cost more than parents expect under L1R5.

What this calculator does not do

It does not show JC, Millennia Institute or polytechnic cut-off points. Cut-off points are different for every school and every course, and they move each year with whoever applies, so any list published here would be out of date and could send you down the wrong path. Check the official MOE and school sources at the time you are choosing.

It does not decide how many bonus points your child earns. MOE publishes the categories and the caps, but not a public breakdown of the points per category, so the calculator asks you for a figure you already know rather than inventing one. Your school can confirm it.

It does not rule on which group a subject belongs to. MOE does not publish the full Humanities and Mathematics or Science subject lists on the pages linked above, so the calculator starts each subject in the obvious group and lets you change it. If a subject on your child's slip is unusual, confirm its group with the school before you trust the total.

It does not compute the polytechnic ELR2B2 aggregate, which is a different calculation with different slots, and it does not check the minimum subject grade requirements for a course.