What Is the PSAT Selection Index?
It's a single number, separate from your 320 to 1520 PSAT score, that National Merit Scholarship Corporation uses to rank students for recognition. The formula is short: add your Reading and Writing section score to your Math section score, multiply that sum by 2, then divide by 10.
That's it. No essay component, no weighting toward one section, no mysterious adjustment. Whatever shows up as your two section scores on your score report is all the formula touches. If you know those two numbers, you can work out your own Selection Index in about ten seconds.
It also doesn't show up anywhere else. Colleges never see it, it has no bearing on how your PSAT score translates to a likely SAT score, and it plays no part in anything the SAT itself measures. The Selection Index exists for exactly one purpose: deciding who gets looked at for National Merit recognition.
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Which choice most logically completes the text?
The Formula, Worked Through With Real Numbers
Say a student scores 670 on Reading and Writing and 670 on Math. Add them: 1,340. Multiply by 2: 2,680. Divide by 10: 268. That's the Selection Index, full stop.
Now take a different student with the same total but an uneven split: 600 on Reading and Writing, 740 on Math. Add them and you still get 1,340. Run the same formula and the index still comes out to 268. Identical. The formula never asks how the total got split between the two sections, only what the total is.
One more thing worth knowing: a 10-point gain is worth exactly the same whether it lands in Reading and Writing or in Math. Start at 650 and 650 for an index of 260, then raise either section to 660, and the index moves to 262 either way. There's no section that counts more in this formula. A point is a point.
Since each section score runs from 160 to 760, the lowest possible index is 64 and the highest is 304. Nobody actually lands at either extreme, but it shows the full range the formula can produce.
National Merit Scholarship Corporation sets a separate qualifying cutoff for each state, not one national number.
Why State Cutoffs Move Every Year
National Merit Scholarship Corporation sets a separate qualifying cutoff for each state, not one national number. A state with a larger pool of high scorers in a given year ends up with a higher cutoff than a smaller or lower-scoring state, because the cutoffs are set to recognize a similar share of top scorers in every state rather than the same raw score everywhere.
That's also why living in a state full of strong test-takers works against you here in a way it never would on the SAT itself. Two students with the identical Selection Index, one in a high-scoring state and one in a lower-scoring one, can land on opposite sides of the cutoff just because of where they go to school.
That also means the cutoff for your state this year isn't locked to what it was last year, or the year before that. It moves with how that year's junior class performed. A number you saw quoted from two cycles ago tells you almost nothing reliable about this year's line, however confident the source sounds.
So treat any specific cutoff you read online as a rough historical data point, not a target. The only place to check current, state-by-state information is National Merit Scholarship Corporation directly, usually through your high school counselor once results are released.
Which PSAT Score Actually Counts
Timing matters as much as the score itself. Only the PSAT/NMSQT taken in the fall of junior year counts toward National Merit. A sophomore sitting, a freshman sitting, or the PSAT 10 given in some schools in the spring, none of those qualify, no matter how high the score comes back.
Not every school offers the PSAT/NMSQT at all, and some offer it on one specific day with no makeup option. Confirm with the school counselor months ahead, not the week of, especially if a student is new to the school or homeschooled and needs to arrange testing through another site.
If a student needs testing accommodations, that request should go in well before the junior year test date, since approval takes time to process. Everything else, like which school administers the test and on what day, runs through the student's own school counselor.
What to Do With Your Index Now
Chasing a specific cutoff number is a losing game, since nobody knows it in advance and it's set after the fact anyway. A better use of the months before the junior year PSAT is raising the actual total that feeds the formula: the combined Reading and Writing and Math score.
That means the same prep that helps on the SAT helps here too, since the two tests share a format and overlapping content. Sort a batch of missed practice questions by skill using StudyPebble's upload tool at /mistakes/upload, or work through weak areas with practice by skill and explanations, and the gains show up on both the Selection Index and whatever SAT comes after it.
For a senior who already sat the qualifying PSAT, none of this applies going forward. The index for that year is locked the moment the test ends. At that point the only thing left to do is wait for National Merit Scholarship Corporation's own timeline and keep preparing for the SAT itself.