What a concordance actually claims
A concordance is a statement about ranks, not about content. It says that a student who scores 1370 on the SAT sits at about the same place in the tested population as a student who scores 30 on the ACT. It does not say the two tests measure the same skills, that the questions are comparable, or that a student who earned one score would necessarily earn the other.
The 2018 tables were built from a large sample of students who took both tests within a short window. ACT and the College Board matched each SAT total to the ACT composite at the same percentile in that joint sample, then smoothed the result into the tables that admissions offices use. Because the sample is students who chose to sit both exams, the concordance describes that overlapping population rather than every test taker in the country.
The practical consequence for an applicant is that the concordance is a translation, not a prediction. It answers "how would an admissions officer read my ACT composite if their benchmarks are in SAT points", which is exactly the question a college with an SAT-heavy applicant pool has to answer about an ACT-only file. It does not answer "what would I score if I sat the other test", because a student's relative strengths across English, mathematics, reading and science do not carry across identically. The ACT's Science section, in particular, has no SAT counterpart, and the SAT's Math section allocates far more of the total to mathematics than the ACT's one-quarter share.
How the table is applied in both directions
Going from ACT to SAT is a straight lookup. Composite 30 has a published concorded SAT total of 1370, so that is the answer; there is nothing to interpolate because ACT composites are whole numbers. This calculator rounds any fractional entry to a whole composite first, because that is what score reports contain.
Going from SAT to ACT needs one extra step, because the SAT scale has far more usable points than the ACT scale. Between an ACT 29 and an ACT 30 there are three reportable SAT totals — 1350, 1360 and 1370 — and every one of them has to land on a whole composite. The calculator inverts the table linearly and rounds. An SAT total of 1300 sits between the row for 27 (1280) and the row for 28 (1310), two thirds of the way up, so the interpolated composite is 27.67 and the reported answer is 28.
That rounding step is why the calculator also reports a band. Every ACT composite corresponds to a run of SAT totals, typically three or four of them spanning 20 to 30 SAT points. Two applicants whose SAT totals differ by 20 points can concord to the identical ACT composite, and the difference simply disappears in the translation. Knowing the band tells you how much headroom you have before your concorded composite moves, which is useful when you are deciding whether one more SAT sitting is worth it.
The final output compares two scores you actually hold. It converts your ACT composite to its SAT value and subtracts that from your real SAT total. A positive number means your SAT total sits above the SAT value of your ACT; a negative number means the ACT composite carries the higher SAT value. Because both scores end up expressed in SAT points, the comparison is like for like.
Worked example: an SAT of 1300 against an ACT of 28
You sat both tests. The SAT came back at 1300 and the ACT at 28, and you have to decide what to send to a college that accepts either.
- Locate 1300 in the SAT column. The table has 1280 against composite 27 and 1310 against composite 28. Your score falls between them.
- Measure the position inside the interval. 1300 − 1280 = 20 SAT points into an interval that is 1310 − 1280 = 30 points wide, so you are 20 ÷ 30 = 0.667 of the way up.
- Interpolate the composite. 27 + 1 × 0.667 = 27.67, which rounds to a reported composite of 28.
- Find the band for composite 28. The midpoint between 1280 and 1310 is 1295, so 1300 is the first reportable total that rounds up to 28. The midpoint between 1310 and 1340 is 1325, so 1320 is the last total that still rounds to 28. The band is 1300 to 1320.
- Convert your real ACT for the comparison. Composite 28 concords to 1310.
- Subtract. 1300 − 1310 = −10. Your ACT is worth ten SAT points more than your SAT total.
Ten points is inside a single band, so on the concordance the two scores are effectively the same. In that position the sensible move is to send whichever score the college's own applicant pool is denser in, or simply to send both. Had the gap been 40 or 50 points — more than one full band — the higher score would be the one to report.
How to read the converted score
Treat a one-composite difference as noise. The concordance bands are 20 to 30 SAT points wide through most of the range, and both tests carry a standard error of measurement of roughly a point on the ACT composite and about 30 points on the SAT total. A conversion that moves you from a composite of 28 to a composite of 29 is inside the joint measurement error of the two instruments.
The compression at the top of the scale is real and often surprising. From composite 33 to 36 the concorded SAT totals run 1460, 1500, 1540, 1590 — steps of 40 to 50 SAT points per composite point, against steps of 30 points lower down. A student at 1500 who gains 40 SAT points moves a full ACT composite; a student at 1080 needs 30 points to do the same. If you are near the ceiling, small SAT gains translate into visible ACT gains and vice versa.
At the bottom the table simply stops. The published concordance runs down to an ACT composite of 9 and an SAT total of 590, and there is nothing below that, because too few students in the joint sample scored there to support a reliable match. The calculator holds scores below the range at the bottom row rather than extrapolating a number that has no evidence behind it.
Finally, remember what the concordance cannot see: section balance. Two students with identical 1300 totals, one with 700 Math and one with 700 Reading and Writing, both concord to 28. If your target programme reads the Math score separately, the translation loses precisely the information that programme cares about. Run your practice raw counts through the SAT raw score to scaled score calculator to see where your sections actually sit before you decide the total tells the whole story.
The 2018 ACT/SAT concordance
| ACT composite | SAT total | SAT points per composite point |
|---|---|---|
| 36 | 1590 | 50 |
| 35 | 1540 | 40 |
| 34 | 1500 | 40 |
| 33 | 1460 | 30 |
| 32 | 1430 | 30 |
| 31 | 1400 | 30 |
| 30 | 1370 | 30 |
| 29 | 1340 | 30 |
| 28 | 1310 | 30 |
| 27 | 1280 | 40 |
| 26 | 1240 | 30 |
| 25 | 1210 | 30 |
| 24 | 1180 | 40 |
| 23 | 1140 | 30 |
| 22 | 1110 | 30 |
| 21 | 1080 | 40 |
| 20 | 1040 | 30 |
| 19 | 1010 | 40 |
| 18 | 970 | 40 |
| 17 | 930 | 40 |
| 16 | 890 | 40 |
| 15 | 850 | 50 |
| 14 | 800 | 40 |
| 13 | 760 | 50 |
| 12 | 710 | 40 |
| 11 | 670 | 40 |
| 10 | 630 | 40 |
| 9 | 590 | — |
The third column is the difference between this row's SAT total and the row below it, computed from the first two columns. It is the SAT cost of one ACT composite point at that level.
Mistakes that produce a misleading conversion
- Using a pre-2016 concordance. The SAT was rescaled in 2016 and the concordance rebuilt in 2018. A table built against the old 2400-point SAT, or against the 1600-point SAT before the redesign, will misplace a score by a full composite point or more.
- Concording section scores with the composite table. ACT and the College Board published separate section concordances for English/Reading against SAT Reading and Writing, and for ACT Math against SAT Math. Running a section score through the composite table gives a number with no standing.
- Averaging two concordance directions. Converting SAT to ACT and back does not always return the original score, because the ACT scale is coarser. That is a property of the scales, not an error, and averaging the round trip does not fix it.
- Treating the concorded score as a predicted score. It describes rank in a joint population, not what you would score on a test you have not taken. Students with strong science reasoning frequently outperform their concorded ACT composite; students whose strength is algebra often outperform their concorded SAT total.
- Reporting the concorded score to a college. Colleges want the score you actually earned, from the testing agency. The concordance is for your own comparison and for admissions offices that choose to apply it internally.
- Ignoring superscoring policy. Many colleges superscore each test separately but do not mix sections across tests. Concording a superscored SAT against a single-sitting ACT compares two differently constructed numbers.
Deciding which score to send
Convert both scores to the same scale, then apply three filters. First, the size of the gap: a difference smaller than one concordance band, which is 20 to 30 SAT points, is not a difference at all. Second, the college's own distribution: if a school's admitted-student profile is reported in SAT points and almost all its applicants send SAT scores, an ACT composite forces the reader to do the translation you have just done, and some readers do it imprecisely. Third, section balance, which the composite hides entirely.
Where the tests genuinely differ is in pacing and in content coverage. The ACT gives less time per question and includes a Science section that is really a data-interpretation section. The digital SAT is adaptive and shorter. Students who read quickly and comfortably tend to find the ACT's timing less punishing, which is why measuring your own rate with the reading speed calculator is a more useful diagnostic than another practice test. If time on task is the constraint, plan the preparation itself with the reading time calculator.
Percentiles are the other common way to compare two scores, and they behave the same way standard scores do everywhere else in psychometrics — the percentile and rarity calculator shows how a fixed mean and standard deviation turn a score into a population rank. And once the testing decision is settled, the financial one is next: the cost of attendance calculator turns a college's published price into the net figure that merit aid, which often keys off exactly these scores, actually leaves you paying.