So, funny story (well my kid did not find it super funny at the time). After doing AP Physics 1 I thought that the Physics subject test would be OK to do so I registered. Then my husband informed me that the AP Physics 1 covers about 40% of what is testing in the Physics subject test. Oops. Kid sat the AP Physics 1 (got a 4, believes missed the 5 by blowing one question). Sat the June Physics subject test after doing 3 x 3 hour prep classes. Kid was somewhat amused that I had signed up for test but since we paid our money decided to indulge me - I figured can always take it again. Got a 750. Will take it again as is doing AP Physics C this year so hopefully will have covered the majority of the topics tested. I guess if you want the 800 you may need more prep that the 3 weeks of light prep my kid had 