career path - Academic rank equivalence between the UK and the US systems

What are the US equivalent ranks to the Lecturer, Senior Lecturer, Reader (or Associate Prof), Professor ranks of the UK system? Is it correct that in the US system they are Assistant Prof, Associate Prof, Full Prof and Chair/Endowed Prof, respectively? I know that in the British system, there are further sub-levels in each of these ranks whereas in the US system there is no further gradation within each rank. So I am looking for only rough equivalence.

Edit: It would be great if a formal/informal reference which compares the two is also pointed out.

Answer

From the wiki pages https://en.wikipedia.org/wiki/Academic_ranks_(United_States) and https://en.wikipedia.org/wiki/Academic_ranks_in_the_United_Kingdom:

1. Entry level position
   
   
   
   • UK: Lecturer
   
   
   • USA: Assistant Professor
   
   
   
   
   


2. Mid-level
   
   
   
   • UK: Senior Lecturer
   
   
   • USA: Associate Professor
   
   
   
   


3. Upper-level
   
   
   
   
   • UK: Reader
   
   
   • USA: Professor
   
   
   
   


4. Highest level
   
   
   
   • UK: Professor
   
   
   • USA: Endowed Chair/Named Professor
   
   
   
   

Note 1. that in the USA, ranks #2 and higher are normally tenured. Tenure is handled different in the British system.

Note 2. The American rank of a named chair (aka named professorship, endowed chair) is distinct from the administrative head of a department, who is also often called the "Chair."