Adjustable backrest

A tiltable chair including a housing, a back support pivotally attached to the housing about a first horizontal axis and a seat support pivotally attached to the housing about a second horizontal axis. A leaf spring includes a first end engaging the housing and a second end biasing the back support and seat support in an upward direction. A fulcrum member is moveably supported in the housing and engages a bottom surface of the spring intermediate the first and second ends of the spring. The chair also include an adjustable backrest and armrests slideably mounted on the back support, and a seat slideably mounted on the seat support. A tilt limiter is provided to limit the rearward tilting of the chair. A selector member includes indicia that indicates the setting of the tilt limiter so as to apprise the user of maximum available rearward tilt position of the chair.