I am often perplexed when I see someone attempting to compare Singapore with the US educational system, because few seem to grasp the differences and it often ends with wrong assumptions and spreading of misinformation. After having my kids go through both systems in their entirety, here are my insights:
Primary 1-4 (ages 7-10) is equivalent to US elementary school, grades 1-6 (ages 6-11).
Primary 5-6 (ages 11-12) is equivalent to US middle school (junior high), grades 7-8 (ages 12-13) which prepares kids for transition to secondary education.
Secondary School (ages 13-16) is US high school (ages 14-17). In fact, most universities in the U.S. (except the most selective ones) accept Singapore secondary school graduation as high school equivalent. My 16 year old nephew was just accepted.
Junior College (ages 17-18) is US prep school. This is not a common educational path in the US because college prep courses in the form of Advanced Placement (AP) can be taken in high school, usually in grades 11-12. Junior College is like taking 100% AP classes, and universities in the US give college credit for APs (just as they often do for H2s from JC as well).
Polytechnic (ages 17-19) is US community college, and while many transfer to university afterwards, you can earn what is known as an associate’s degree after 2 years, equivalent to a poly diploma, and similarly — both certs don’t have great international recognition, only local.
Technical Institute is US vocational school. This is an optional path high schoolers can take during grades 11-12 (although it has far less stigma than Singapore). I went down this path myself, taking construction and CAD/CAM. I then moved on to community college, and two years later, university. It was the perfect path for a late bloomer like me.
So there you go. Hopefully this clears up any confusion that anyone might have.