Rules of thumb for hammock chairs:
1.The larger the chair, the greater its confort!
2.The spreader opens the hammock chair: the longer the spreader the more elbow-room and the more freedom of movement for the body, also allowing a wider variety of sitting positions.
3.The length of the seat (for woven hammock chairs this represents the width of the cloth from selvedge to selvedge) determines primarily which parts of the body can be supported.

Hint:
For security reasons a hanging chair should be fitted with an intergrated swivel.

What you should know:
100-130 cm seat length= hammock chair allows room for back and backside.
140-170cm Seat length= hammock chair has plenty of room for back and backside, head is supported.
Seat length 180cm and more = even the legs fit into the chair.