A parent asks us this every fall: my child is in 9th grade and strong at math, should they take the AMC 10 or the AMC 12? The honest answer depends on three things, and none of them is which one looks more impressive. Here is how to decide.
The two tests are closer than they sound
Both contests are 25 multiple-choice questions in 75 minutes, with no calculator or formula sheet. A correct answer is worth 6 points, a blank is worth 1.5, and a wrong answer is worth 0, so the top score is 150. The same organization writes both, the Mathematical Association of America, and both are offered on two dates each year, an A date and a B date. For the 2026-27 season those dates are Thursday, November 5, 2026 and Friday, November 13, 2026.
The difference is in the problems. The AMC 10 stays inside algebra, geometry, counting, probability and number theory that a student has met by the end of Algebra 2 at the latest, and most of it by the end of Geometry. The AMC 12 adds precalculus topics such as trigonometry, logarithms, complex numbers and more demanding function work, and its middle problems are harder than the AMC 10's.
Who is eligible
The AMC 10 is open to students in grade 10 or below who are 17.5 years old or younger on contest day. The AMC 12 is open to students in grade 12 or below who are 19.5 or younger. That means a 9th grader can take either test. A 7th or 8th grader can take either as well, but be honest about whether the student has the content for it.
One more rule worth knowing: you do not register with the MAA yourself. A school, math circle, university or learning center registers as a testing site and registers students. Homeschools cannot be sites, and there is no remote proctoring, so a homeschooled student needs a school, learning center or math circle that is registered. Parents register their child through a link the site sends. If your child's school does not host the contest, ask a math teacher or the math department whether they can, or look for a local site.
The real question: what is the goal?
Most families have one of three goals, and each points to a different choice.
Goal one: reach AIME
The AIME is the next stage of the contest sequence, a 15-question exam in two parts, 8 questions and then 7, three hours in all, whose answers are whole numbers from 0 to 999. It is taken on a computer at a Pearson test center, and the MAA emails invitations in mid-December 2026 once AMC scores are final. To be invited, a student needs a score of 100 or higher on the AMC 10 or 85 or higher on the AMC 12, and a student must be at least 13 on AIME day.
Look at those two numbers together. The AMC 12 threshold is lower because the test is harder. Blanks make the arithmetic friendlier than it looks. On the AMC 12, 11 correct answers with the other 14 left blank is 87 points, and 14 correct with 1 blank is 85.5. On the AMC 10, 14 correct answers with the other 11 blank is 100.5. So the real difference is how many problems you can solve cleanly, and the AMC 12 asks for fewer of them. A strong 10th grader who has finished a precalculus unit often has a better chance of qualifying through the AMC 12 than the AMC 10. A 9th grader who has not seen trigonometry has little reason to prefer the AMC 12.
Goal two: a clear signal on a transcript
If the aim is simply to show sustained interest in math, either contest does that. A strong score on the AMC 10 in 9th and 10th grade, followed by the AMC 12 in 11th grade, tells a cleaner story than a single high-risk attempt. Admissions readers tend to see the arc, not the single number. Consistency matters more than which test you sat in any one year.
Goal three: a learning experience
Many students take the AMC 10 simply to find out how it feels to work on problems with no obvious method. For that goal, the AMC 10 is better in almost every case. The AMC 12 has fewer problems a student can start from scratch without formal precalculus, which makes the experience more frustrating than useful for a first attempt.
A simple decision rule
Use this checklist of content, not of confidence.
If your student has finished Geometry and is in or past Algebra 2, and has already done well on the AMC 8 or school contests, start with the AMC 10. If the student has finished Algebra 2 and is in Precalculus now or has done it already, and scored in the top range on a prior AMC 10, consider the AMC 12 in the same year or the next.
A student may take both an A and a B contest in the same year, for example the AMC 10A and then the AMC 12B, or the 10A and then the 10B. What is not allowed is taking the AMC 10 and the AMC 12 on the same day. Check that your school offers the date you want and that it does not conflict with other exams. For some students the second attempt is stronger because the first removed the surprise.
What a score tells you
A first attempt well under 100 is not a sign the student is behind. It usually means the student is solving a share of the problems and leaving the rest. The first goal for most students is not 100. It is to finish the first fifteen problems reliably and without careless errors. Those fifteen problems are where most of a typical score comes from.
The blank-answer credit matters here. Because a blank earns 1.5 points and a wrong answer earns 0, a student who guesses on a problem they cannot start loses on average. With a one-in-five chance of a correct guess, the expected value of a guess is 1.2 points, below the 1.5 points for leaving it blank. In practice, guess only after you have eliminated at least two of the five choices.
What to do in the months before
Start from the real thing. Past AMC 10 and AMC 12 papers are available from the MAA and from the Art of Problem Solving, and are the best preparation source because the style never changes much. Take one under timed conditions, mark every problem you got wrong or skipped, and sort the mistakes into three piles: careless, did not know the method, and ran out of time. Spend your next two weeks on the second pile and your next two on the first.
A good schedule for the fall contest is four to six weeks of timed practice, one full test every week or two, and a longer review session after each. Students who take a test and never review it improve slowly. Students who review every problem, even the ones they got right, improve faster.
What we would do for a typical family
A strong 9th grader who has taken Geometry and did well on the AMC 8: take the AMC 10. Do not worry about the AMC 12. Spend the year on algebra and counting, because those two topics carry the AMC 10.
A strong 10th grader who has finished Algebra 2: take the AMC 10, and consider the AMC 12 on a different date if the school offers it, because the qualifying threshold is lower.
An 11th or 12th grader with a precalculus background: take the AMC 12. The AMC 10 is only open to students in grade 10 or below.
An 8th grader who is excellent: take the AMC 8 (January 21 to 27, 2027) and the AMC 10 the next fall. The AMC 8 is a gentler first contest, and our free Mock AMC 8 gives a full score report so you can see where the student stands before they sit the real thing.
We are building a free AMC 10/12 diagnostic with a timed mock and a score report that shows how a student's score compares with the AIME qualifying score. If you would like to be told when it opens, join the list on our AMC 10 and 12 page. Our next article explains what score qualifies for the AIME.