How the ACT composite is calculated
Each ACT section is scored from 1 to 36. Your composite is the average of the sections that count, rounded to a whole number. ACT's rule: Fractions less than one-half are rounded down; fractions one-half or more are rounded up.
So 27.5 becomes 28 and 27.25 becomes 27.
Enhanced ACT (September 2025 and later)
ACT says the composite is the average of your English, math, and reading scores, rounded to the nearest whole number.
Science is optional and gets its own score. You also get a STEM score, the average of math and science. ACT started removing science from the composite for national online tests in April 2025, and every test used the new calculation by September 2025.
composite = round((English + Math + Reading) ÷ 3)
Legacy ACT (before the change)
The older test averaged all four sections: English, math, reading and science, divided by 4, with the same rounding rule.
composite = round((English + Math + Reading + Science) ÷ 4)
Sources: Understanding Your ACT Scores and How to Calculate Your ACT Superscore, both from ACT. ACT also tells colleges that composites with and without science are comparable. Read ACT's notes for colleges.
Worked example
Enhanced ACT: English 34, math 35, reading 33. (34 + 35 + 33) ÷ 3 = 102 ÷ 3 = 34.
Legacy ACT with science 32 added: (34 + 35 + 33 + 32) ÷ 4 = 134 ÷ 4 = 33.5. The fraction is one-half, so it rounds up to 34.
Rounding down: English 30, math 30, reading 31 is 91 ÷ 3 = 30.33, a composite of 30. One more point anywhere makes it 92 ÷ 3 = 30.67, which rounds to 31.
Common questions
Is science part of the ACT composite now?
Not on the enhanced ACT. Since September 2025, the composite is English, math and reading. Science is optional and reported as its own score, and it feeds into your STEM score with math.
Does a .5 average round up on the ACT?
Yes. ACT rounds fractions of one-half or more up and anything less down. A 27.5 average is a 28 composite.
How many points do I need to raise my composite by one?
It depends on where your average lands. On the enhanced ACT, you need your three-section total to reach (next composite − 0.5) × 3, rounded up. The calculator shows how many section points that is.
Can colleges compare enhanced and legacy ACT scores?
ACT says composite scores with and without science are comparable. If you took both versions, many colleges will look at your best scores. Check each college's testing policy.
What is a superscore?
Your best section scores from different test dates, averaged into one composite. Some colleges accept it and some don't. Use the superscore calculator to work it out.
How does my ACT compare to the SAT?
Use the official ACT/SAT concordance. The SAT to ACT converter has the full table.