What does a US High School Diploma compare to in the UK?

Hello I am moving to London and I graduated High School in Sacramento CA and I want to go for a bachelors but I don't know if I qualify with a US High School diploma alone, maybe there is more required in the UK before you can study at bachelors level. Can anyone help me?

It is usually considered approximately equivalent to 5 GCSE qualifications (grades A*-C), which are 2-year courses in various subjects that UK students take at age 14-16.

If they want to go onto university after that, they have to take 2 more years of advanced course (A levels) in 3-5 subjects (age 16-18) - these A levels are approximately equivalent to US AP classes (at score/level 5) or the first year or two of US college.

To study at university in the UK, you need decide on your major before you apply as you have to apply to study a specific course/subject in a specific department. Most people have to apply through UCAS - the website is here if you want to take a look and find out more about applying for a bachelors in the UK: http://www.ucas.com/

If you want to see what your US qualifications are actually equivalent to the UK, it might be worth contacting NARIC and get them to translate them properly (http://www.naric.org.uk/).

Did you take any AP courses?  If you did, then you can use them to apply to UK universities along with your degree.  The students as my school in London (all doing American curriculum) have no problem getting into UK universities if they have decent AP scores (usually need a 4 or 5 to get into a decent school).  Without AP scores you will have a problem getting in.