ACT to IQ at a glance

An ACT composite of 28 points to an IQ of about 114, with a likely range of 102–127. A 24 points to about 109 (97–122), and a 34 to about 123 (110–135).

Like every score-to-IQ conversion, this is an estimate. The ACT correlates about .77 with a general-ability score in the best published study, which is strong but leaves plenty of room for people who are sharper or weaker than their score suggests. If the ACT were a perfect IQ measure, a 28 would mean IQ 119.

Notable ACT scores and the IQ they point to
ACT score	Percentile among test-takers	Estimated IQ	Likely range
16	39th	98	86 to 111
18	51th	101	89 to 114
20	62th	104	92 to 117
22	72th	107	94 to 119
24	80th	109	97 to 122
26	87th	112	100 to 125
28	91th	114	102 to 127
30	94th	117	104 to 129
32	97th	119	107 to 132
34	99th	123	110 to 135
35	99th	124	112 to 137
36	100th	132	120 to 145

ACT to IQ conversion chart

Every row below comes from the same model as the calculator. The likely range covers about four in five people at that score. The last column shows what the IQ would be if the ACT were a perfect measure of IQ, which is the number many other converters publish.

ACT to IQ chart (Composite 1 to 36, the rounded average of the section scores)
ACT score	Test-taker percentile	Estimated IQ	Likely range	If a perfect measure
14	24.5	94	82 to 106	91
15	32	96	84 to 109	94
16	39	98	86 to 111	97
17	45	100	87 to 112	99
18	51	101	89 to 114	101
19	57	103	90 to 115	103
20	62	104	92 to 117	105
21	67	105	93 to 118	107
22	71.5	107	94 to 119	109
23	76	108	96 to 121	111
24	80	109	97 to 122	113
25	84	111	99 to 123	115
26	86.5	112	100 to 125	116
27	89	113	101 to 126	118
28	90.7	114	102 to 127	119
29	92.3	115	103 to 128	121
30	94	117	104 to 129	123
31	95.3	118	105 to 130	124
32	96.7	119	107 to 132	127
33	98	122	109 to 134	130
34	98.5	123	110 to 135	131
35	99	124	112 to 137	134
36	99.9	132	120 to 145	144

IQ to ACT: what score to expect

Going the other way, this table shows the ACT score people at each IQ typically get. Scores at the same IQ vary widely, so the range matters more than the middle figure.

Typical ACT score by IQ
IQ	Typical ACT score	Likely range	How rare is this IQ
85	13	11 to 18	1 in 6 at or below
90	15	11 to 20	1 in 4 at or below
100	17	13 to 24	1 in 2 at or above
110	21	15 to 28	1 in 4 at or above
115	23	17 to 30	1 in 6 at or above
120	25	18 to 32	1 in 11 at or above
125	27	20 to 34	1 in 21 at or above
130	30	22 to 35	1 in 44 at or above
135	31	24 to 36	1 in 102 at or above
140	33	26 to 36	1 in 261 at or above
145	35	29 to 36	1 in 741 at or above

One IQ, several tests: ACT next to other scores

The same IQ shows up as very different numbers on different tests. This table shows the typical score at each IQ on ACT and on the tests closest to it. Read across a row to compare, for example, what an SAT and an ACT would each be for the same person.

Typical score by IQ across ACT, SAT, GRE, ASVAB, LSAT
IQ	ACT	SAT	GRE	ASVAB	LSAT
100	17	990	298	50	148
110	21	1140	306	70	153
120	25	1280	315	86	159
130	30	1410	323	95	164
140	33	1530	332	98	169

These are typical scores, not guarantees. Every test has its own likely range, shown on its page.

What the ACT measures and how it relates to IQ

The ACT tests English, maths and reading, and historically science reasoning, in a timed multiple-choice format. It is closer to a school-achievement test than the SAT is: the maths section assumes algebra, geometry and some trigonometry, and the English section tests grammar conventions.

Even so, ACT scores track general ability closely. Koenig, Frey and Detterman (2008) matched ACT composites to a general-ability score built from the ASVAB for 1,075 people in a national US sample and found a correlation of .77. In a smaller sample of 149 students who also took Raven's Advanced Progressive Matrices, the correlation was .61.

The gap between .77 and .61 is informative. The ACT relates less strongly to a pure reasoning test than to a broad battery that also samples vocabulary and arithmetic. That is one reason this converter uses a correlation of .72 rather than the higher figure.

The 2025 ACT changes and which norms this uses

From 2025 the ACT was shortened and Science became optional. The composite for most students is now the average of English, Math and Reading only. ACT has not yet published national norms for that three-section composite.

This converter uses the Class of 2025 profile, which for most students still reflects the four-section composite. If you took the newer version, treat the result as approximate. The direction and the general size of the estimate should hold, but a point or two in either direction is inside the uncertainty anyway.

One more thing changes the picture: several US states have every student take the ACT at school, so the pool includes many students who would not have chosen to sit it. That pulls the average score down and makes the test-taker pool closer to the general population than the pool for a voluntary test.

ACT or SAT: which one converts better?

Neither is clearly better as a stand-in for IQ. The SAT has more published evidence linking it to general ability, largely because of the older studies, but the ACT correlates about as strongly in the study that measured it. If you have both scores, the two estimates should land within a few points of each other; use the SAT to IQ converter for the other one and treat any gap as noise.

Mensa is a useful reference. American Mensa accepted an ACT composite of 29 for tests taken before September 1989 and accepts no ACT scores after that date. A 29 today would sit at about the 91st percentile of test-takers, so that historical bar corresponded to a much narrower group than the modern pool.

What your ACT composite means

Percentiles compare you with other 2025 test-takers. The estimated IQ column shows the most likely value, with the likely range in brackets.

What ACT score bands mean
Score	Estimated IQ	What it means
1 to 15	68 to 96	Below the middle of test-takers. Scores here reflect gaps in school knowledge or test conditions as often as low ability, and the estimated IQ is only a little below average.
16 to 20	98 to 104	Around the middle. The national mean is 19.4, so this band holds a large share of all test-takers and the estimated IQ is close to 100.
21 to 25	105 to 111	Above average. Roughly the 67th to 84th percentile of test-takers, with an estimated IQ in the low to mid 100s.
26 to 29	112 to 115	Strong: roughly the top 15% to the top 8%. The estimated IQ moves into the 110s.
30 to 33	117 to 122	Top 6% down to the top 2%. Competitive for selective colleges. The estimated IQ is around 115 to 125.
34 to 36	123 to 132	The top 1%. A 36 is so common among the very top that it says less about ability than the number suggests, and a wide range reflects that.

Why a ACT score is not an IQ

It leans on school contentMore of the ACT than the SAT depends on what you were taught in maths and English classes. Strong reasoning with weak preparation lowers the score, and heavy preparation raises it.
Scores are coarse at the topThe composite runs from 1 to 36 in whole steps, so many people share each score near the top. A 35 and a 36 are often indistinguishable in ability.
The test changed in 2025With Science optional and the test shortened, the composite is built from fewer sections. Older research, and the norms used here, describe the four-section version.
The correlation is not oneAt .72 the ACT explains about half the variation in IQ among test-takers. The rest is other abilities, knowledge, motivation and chance on the day.

The evidence behind these numbers

Evidence grade: Moderate

A published comparison exists, in the same research group and design as the SAT study. It used a general-ability score from a military battery and a pre-2025 ACT, not a Wechsler test on the current exam.

Published facts we used

ACT composite and ASVAB-derived general ability: r = .77 (N = 1,075; Koenig, Frey and Detterman, 2008).
ACT composite and Raven's Advanced Progressive Matrices: r = .61 (N = 149).
Class of 2025 composite mean 19.4, SD 5.9, N = 1,380,130 (ACT profile report).
Cumulative percentiles for each composite score.

Assumptions we made

Mean IQ of ACT test-takers: 101. About a third of US graduates take the ACT, and several states test every student, which keeps the pool close to the general population.
IQ spread among test-takers: SD 14.
Correlation between ACT and IQ among test-takers: .72, between the two published values and lowered for selection.

Assumed test-taker IQ: mean 101, SD 14
Assumed correlation (r): 0.72
Likely range: The score at which about 80% of people with that estimate fall, from the residual spread after regression
Norms: ACT profile report, graduating class of 2025.

ACT to IQ: frequently asked questions

What ACT score equals an IQ of 130?+

People with an IQ of 130 typically score around 30 on the ACT, and about four in five land between 22–35. Above 30 the composite is coarse, so the top of the range is capped at 36.

Is a 28 ACT a high IQ?+

A 28 is in the top the top 9% of test-takers. It points to an IQ of about 114, most likely within 102–127. That is clearly above average but not proof of a very high IQ.

Is the ACT an IQ test?+

No. It is a curriculum-linked college readiness test. It correlates about .77 with a general-ability score in the best published study, so it tells you something about IQ but not precisely.

What ACT score is 140 IQ?+

A person with an IQ of 140 typically scores about 33 on the ACT, with a likely range of 26–36. The composite tops out at 36, so many people with high IQs cannot score higher.

Does Mensa accept the ACT?+

Only old scores. American Mensa accepts an ACT composite of 29 for tests taken before September 1989. It accepts no ACT scores after that date.

Does the new three-section ACT change the conversion?+

The scale is still 1 to 36, but ACT has not yet published norms for the three-section composite. This converter uses the Class of 2025 norms, so treat results for the newer composite as approximate.

References & Sources

Koenig, K. A., Frey, M. C., & Detterman, D. K. (2008). ACT and general cognitive ability. Intelligence, 36(2), 153-160. https://www.sciencedirect.com/science/article/abs/pii/S0160289607000487
ACT (2025). The ACT profile report: graduating class of 2025, national. ACT, Inc.. https://www.act.org/content/dam/act/unsecured/documents/2025-act-profile-report-us.pdf
American Mensa (2026). Qualifying test scores. us.mensa.org. https://www.us.mensa.org/join/testscores/qualifying-test-scores/
Frey, M. C., & Detterman, D. K. (2004). Scholastic assessment or g?. Psychological Science, 15(6), 373-378. https://journals.sagepub.com/doi/abs/10.1111/j.0956-7976.2004.00687.x