Different organizations seem to compare SAT and ACT scores differently. However, here is the basic comparison chart for ACT and SAT scores. With this chart you can compare between ACT, old SAT, and new SAT scores.

ACT -> Old SAT -> New SAT with Writing
36 -> 1600 -> 2400
35 -> 1560 to 1590 -> 2340 to 2390
34 -> 1520 to 1550 -> 2280 to 2330
33 -> 1480 to 1510 -> 2220 to 2270
32 -> 1440 to 1470 -> 2160 to 2210
31 -> 1400 to 1430 -> 2100 to 2150
30 -> 1360 to 1390 -> 2040 to 2090
29 -> 1320 to 1350 -> 1980 to 2030
28 -> 1280 to 1310 -> 1920 to 1970
27 -> 1240 to 1270 -> 1860 to 1910
26 -> 1200 to 1230 -> 1800 to 1850
25 -> 1160 to 1190 -> 1740 to 1790
24 -> 1120 to 1150 -> 1680 to 1730
23 -> 1080 to 1110 -> 1620 to 1670
22 -> 1040 to 1070 -> 1560 to 1610
21 -> 1000 to 1030 -> 1500 to 1550
20 -> 960 to 990 -> 1440 to 1490
19 -> 920 to 950 -> 1380 to 1430
18 -> 880 to 910 -> 1320 to 1370
17 -> 840 to 870 -> 1260 to 1310
16 -> 800 to 830 -> 1200 to 1250
15 -> 760 to 790 -> 1140 to 1190
14 -> 720 to 750 -> 1080 to 1130
13 -> 680 to 710 -> 1020 to 1070
12 -> 640 to 670 -> 960 to 1010
11 -> 600 to 630 -> 900 to 950

I found this comparison here: http://en.wikipedia.org/wiki/SAT

Another comparison can be found at official state website of New Jersey here:
http://phs.prs.k12.nj.us/guidance/SAT_ACT_Comparison.pdf

Official Collegeboard.com ACT/SAT scores concordance is available on this PDF file:
http://professionals.collegeboard.com/profdownload/act-sat-concordance-tables.pdf