Accuracy of ACT/SAT score conversions

Test Preparation
1

<p>The collegeboard has a chart posted that converts ACT and SAT scores to each other and says it's based on common percentile ranks, but the chart is extremely inaccurate. Using both the graphs of percentiles from collegeboard.com and act.org, I am going to compile a more accurate picture of score conversion.</p>

<p>ACT SAT PERCENTILE</p>

<p>36 1600 99
35 1580-1590 99
34 1550-1570 99
33 1520-1540 99
32 1480-1510 99
31 1450-1470 98
30 1420-1440 97
29 1380-1410 95
28 1340-1370 93
27 1310-1330 90
26 1260-1300 86
25 1230-1250 82
24 1190-1220 77
23 1150-1180 71
22 1110-1140 64
21 1070-1100 57
20 1030-1060 50
19 990-1020 42
18 940-980 34
17 900-930 27
16 850-890 20
15 800-840 14
14 750-790 9
13 680-740 5
12 590-670 2
11 570-580 1
10 550-560 1
9 530-540 1
8 510-520 1
7 490-500 1
6 470-480 1
5 450-460 1
4 430-440 1
3 420 1
2 410 1
1 400 1</p>

<p>Furthermore, you can approximate even further your SAT score using your original ACT score by finding the exact score you earned by adding up your test scores and dividing by 4 and not rounding the result. For example, a score of 32 spans 1480-1510. If you scored a 31.5, you are on the bottom end of the 32 score range (1480), whereas a 32.25 would be on the upper range (1510).</p>

2

<p>it doesn't matter how you feel it should be done, it depends on what the adcoms use. Maybe they use act's or cb's conversion, or maybe they use their own. secondly, you can't just divide them, using percentiles is the closet possible way.</p>

3

<p>Let's not trust the statisticians of ACT and SAT and make our own scales!!! Yippee!</p>

4

<p>i'm still not sure why anyone would. What's the point, for the fun of it all?</p>

5

<p>I didn't just divide them, I compared the percentiles. The collegeboard has a chart that shows them here : <a href="http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2003/pdf/table_3b.pdf%5B/url%5D"&gt;http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2003/pdf/table_3b.pdf&lt;/a&gt;&lt;/p>

<p>And ACT has one here :
<a href="http://www.actstudent.org/scores/norms1.html%5B/url%5D"&gt;http://www.actstudent.org/scores/norms1.html&lt;/a&gt;&lt;/p>

<p>This chart, <a href="http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2002/pdf/ten.pdf%5B/url%5D"&gt;http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2002/pdf/ten.pdf&lt;/a>, that claims to convert them using percentiles doesn't actually follow them. For example, the first time I took the ACT, I got a 30 which is 97th percentile. Apparently a 30 is a 1340 SAT which is 93rd percentile according to the collegeboard. 93 does not equal 97.</p>

6

<p>percentiles change every year for both tests though! And I still don't understand why you would make your own conversion chart</p>

7

<p>You make a good point. If you base it strictly on percentiles, you are right. But the percentiles are based on different groups. For ACT, it is composed of 11 and 12 graders, where SAT is just college bound 12, which means SAT test takers have more ability, thus the cause for the difference. Also, CB bases the comparison on people who took both the ACT and SAT, which is quite accurate.</p>

8

<p>Your scale is wrong. A 30 should equal, if you go by percentiles, a 1380. A 1380 is the 95th percentile and a 30 is the 95th percentile. I'm not too sure why ACT says 97th percentile when 57637/1171460 is definitely .0492 (~5%) so 100-5=95.</p>

<p>If you don't believe me, do the calculations yourself:</p>

<p><a href="http://www.act.org/news/data/04/pdf/t4.pdf%5B/url%5D"&gt;http://www.act.org/news/data/04/pdf/t4.pdf&lt;/a>
<a href="http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2003/pdf/2003CBSVM.pdf%5B/url%5D"&gt;http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2003/pdf/2003CBSVM.pdf&lt;/a&gt;&lt;/p>

9

<p>I did the calculations on the page, and it still is 97th percentile.
Look: 1171460 students took the ACT last year.
The amount that scored 30 or below can be found by subtracting the number of students that scored 31 or higher on their composite from the total of test takers.
1171460-224-1619-3590-6586-10183-14620 = 1134638</p>

<p>1134638 / 1171460 x 100 = 96.86 ~ 97.</p>

10

<p>And I have a score report that doesn't lie. 30 ACT is at or better than 97% of test takers.</p>

11

<p>I like your conversion better. It makes more sense, at least when my scores are converted. I got a 1480 on the SATs, but when I took the ACT, I scored a 30, which translates to a 1380, a difference of 100 points. I guess it varies from person to person.</p>

12

<p>Oh yeah, and another thing that may account for the varying in ability is the fact that many ACT test takers are forced to take it (Prarie State Achievement Test), where I don't think anyone is forced to take the SAT.</p>

13

<p>that chart is more generous than the uc conversion table</p>

14

<p>You really need to go to that conversion table the College Board has on its site and read the small print at the bottom where it says, "Data is based on 103,525 test-takers who took both the SAT and ACT between October 1994 and December 1996." It was an accurate percentile comparison then but there have been changes to the SAT which have shifted its scores since that time. In other words, that table (and others you will find on-line are just copies of that one) is greatly outdated. The College Board does not claim it is actually accurate today. </p>

<p>As far as colleges actually using it, a number still do, many create their own conversion tables based on more modern data, and many simply do not try to make a comparison. The way to get an idea about what any particular college may actually be doing today is to look at their middle 50% SAT scores and ACT scores. For some, they will look like that table, for many others the comparison is closer to today's percentile equivalencies.</p>

15

<p>I've seen a different scale with 1350 being a 30. (I distinctly remember)</p>