An office chair comprising:
- a base device including two bottom side portions opposite to each other in a left-to-right direction, two top side portions opposite to each other in the left-to-right direction and disposed above and spaced apart from said bottom side portions, two rear side portions opposite to each other in the left-to-right direction and each connected between a rear end of a corresponding one of said bottom side portions and a rear end of a corresponding one of said top side portions, and two front side portions opposite to each other in the left-to-right direction and each connected between a front end of the corresponding one of said bottom side portions and a front end of the corresponding one of said top side portions;
- a seat device including a fixed seat section disposed fixedly between said bottom side portions and having opposite front and rear sides, a rear seat section connected pivotally to said rear side of said fixed seat section, a front seat section connected pivotally to said front side of said fixed seat section, and an invertible seat section connected pivotally to a side of said front seat section distal from said fixed seat section;
- and
- a leg device mounted on and under said base device and adapted to be disposed on a support surface;
- wherein said seat device is convertible among a first state, where said rear seat section is disposed uprightly and removably between said rear side portions, where said front seat section is disposed uprightly and removably between said front side portions, and where said invertible seat section is disposed horizontally and removably between said top side portions, so as to allow a user to sit thereon, in such a manner that feet of the user are suspended from said invertible seat section, a second state, where said rear seat section is disposed uprightly and removably between said rear side portions, where said front seat section is spaced apart from said front side portions and extends forwardly from said fixed seat section, and where said invertible seat section is spaced apart from said top side portions and extends forwardly from said front seat section, so as to allow the user to sit on said fixed seat section, in such a manner that the feet of the user rest on said front seat section and said invertible seat section, and a third state, where each of said front seat section and said invertible seat section is at a position the same as that in the second state, and where said rear seat section is inclined, and extends rearwardly and upwardly from said fixed seat section, so as to allow the user to lie on said seat device, in such a manner that a back of the user rests on said rear seat section.