ACT Composite Score Calculator

Background.

Since September 2025 the ACT Composite has been the average of three section scores, not four. English, math and reading are added, divided by three and rounded to the nearest whole number; science, now an optional section, is reported on its own and no longer moves the Composite. Students who sat an online national test from April 2025 were already scored this way, while anyone who tested on paper or on a school day before that autumn received the older version, the average of all four sections. A score report prints a single Composite with no label saying which formula produced it, so the test date is the only way to tell.

That is why two Composites come back from the same four section scores. ACT calls them EMR (English, math, reading) and EMRS (the same plus science), and for most students they land on the same number. ACT's research found that the two correlate at 0.99 and, for every legacy Composite above 13, line up point for point; if every student took science, it expects more than 90% would score within one point under both formulas. Within one point is not the same as identical, though, and when a scholarship or program draws its line at a particular Composite, one point is the whole question.

The rounding follows ACT's published rule: a fraction below one-half goes down, one-half or more goes up. Under the current formula that rule never meets a tie, because a total of three whole numbers divided by three can only end in .00, .33 or .67. Ties belong to the legacy formula. Dividing by four produces averages ending in .5, and a student whose four sections add up to 98 sits on exactly 24.5, which ACT rounds up to 25. The STEM score, the average of math and science, can also land on a half and is rounded the same way.

Everything here starts from scaled section scores on the 1–36 scale, the numbers printed on a score report or produced by a practice test's own scoring table. Turning a count of correct answers into a scaled score is a separate step: ACT equates every test form individually, so the same number of correct answers can convert to different scores on different dates, and no single conversion table applies. The optional writing test, scored from 2 to 12, never enters any of these averages.

What is act composite score calculator?

The ACT Composite is a single score from 1 to 36 that summarizes a student's results across the core sections of the ACT. Each section is reported on the same 1–36 scale, and the Composite is their rounded average: English, math and reading on the enhanced ACT introduced in 2025; English, math, reading and science on the legacy test it replaced. ACT's linking study concluded that section scores from the two versions are interchangeable, and it reports the two Composites interchangeably too, printing only one of them on any report. The STEM score is a separate summary, the rounded average of the math and science scores, reported only to students who take the science section. Colleges and scholarship programs may still weigh science and STEM scores even though science no longer counts toward the Composite.

How to use this calculator.

1. 01Copy the four scaled section scores from your score report or from a practice test's scoring table: English, Math, Reading and Science, each a whole number from 1 to 36. Do not enter the number of questions you answered correctly.
2. 02If you did not take science, put any value from 1 to 36 in the Science box. The field needs a number, but the current Composite ignores it; disregard the legacy Composite and the STEM score in that case, since both depend on the science value you typed.
3. 03Read the current Composite first. It is the figure on any report from an online national test since April 2025 or from any test date since September 2025.
4. 04Use the legacy Composite to compare against a report from before the change, such as your own first attempt on a paper test in spring 2025 or an older sibling's scores.
5. 05To preview a superscore, enter your best English, math and reading scores from different test dates. ACT now builds its superscore the same way, from the best score in each section regardless of which version of the test it came from.

The formula.

Current Composite = round((E + M + R) ÷ 3). Legacy Composite = round((E + M + R + S) ÷ 4). STEM score = round((M + S) ÷ 2). E, M, R and S are the scaled English, math, reading and science scores, and round means to the nearest whole number with a half going up, the rule ACT states on its Understanding Your Scores page.

Because every input is a whole number, each Composite covers a short run of possible section totals. Under the current formula a Composite of N comes from an English-math-reading total of 3N − 1, 3N or 3N + 1: a 24 is any total from 71 to 73, and a 25 needs 74 to 76. Under the legacy formula the run is four totals long, 4N − 2 to 4N + 1, so a legacy 25 covers totals of 98 through 101. Those bands are what matter when planning a retake. A student whose three sections total 73 is one scaled point from the next Composite, in whichever section it comes from; a student at 71 needs three.

The gap between the two Composites comes down to how far science sits from the other three sections. Adding science to the average shifts it by a quarter of the difference between the science score and the English-math-reading average. A science score four points above that average lifts the legacy result by about a point, and one four points below pulls it down by about a point. At the extreme, a student with 20 in English, math and reading and 36 in science has a current Composite of 20 and a legacy Composite of 24, the kind of profile for which the separately reported science and STEM scores are worth sending.

A worked example.

Frequently asked questions.

References& sources.

1. [1]ACT Education Corp (2025). "Interpreting Scores on the Enhanced ACT: Guidance for K-12 and Higher Education Institutions." Source of the EMR/EMRS Composite formulas, the STEM score definition, and the transition timeline.
2. [2]ACT — Understanding Your Scores. Official page stating the round-half-up rounding rule for the Composite score.
3. [3]ACT — ACT Test Enhancements for Higher Education. Official overview of the Enhanced ACT changes, including the optional Science section.
4. [4]ACT and PreACT Changes and Enhancements for K-12 Educators. Official K-12-facing summary of the Enhanced ACT rollout timeline.
5. [5]U.S. Department of Education, National Center for Education Statistics (NCES) — Handbook of Survey Methods. General federal reference on standardized test score reporting conventions.