How much can I expect my LSAT score to jump?

I’m an undergrad junior at the moment, trying to decide whether I want to take the law path. If I do decide this is what I want, I will go a totally different route for the rest of my undergrad (I will completely switch my major, etc). I decided I only want to go to this route if I can score a 170+ on my LSAT. However, I would be taking this LSAT after I graduate and I want to know NOW before I totally switch the rest of my undergrads route that I can someday accomplish this 170+. I am going to try to test this by, in May, studying intensely for 1 month using books purchased online, and then giving myself a “diagnostic LSAT” to gauger my scoring. I told myself if I get a 163+ on this diagnostic LSAT, I will be able to “work with that” and eventually get a 170+ when the real time comes. For the real LSAT down the line (probably 1.5-2 years from now), I am going to study for much longer than 1 month and not only study independently using books/old practice tests but also do a course of private tutoring (most likely I would do Powerscore for the private tutoring)

In terms of my May diagnostic score, is a 163+ as a diagnostic a good number for me to say with intense studying bringing it up to a 170+ is reasonable?

Every student is different, but both my S and my D started with 164 on their diagnostic exams and achieved 170+ on their official LSATs. Each did take a commercial test prep course; one used Kaplan and the other used Powerscore.

I would take a test cold, and then guess that you’ll go up by a few points. Kaplan and other test prep classes advertise projected increases in LSAT scores due to taking their classes, and so you may wish to see what claims they make and figure that your increase will in their ballparks. A month of studying would help somewhat so if you study and then take the test, a class might not boost your score a whole lot more.

I highly recommend The LSAT Trainer by Mike Kim. My practice test scores have already jumped significantly from using his book. It’s totally different than anything else I’ve used.