Lots of factors have to be taken into consideration to give a fair answer,
type of carpet, obstructions , Ie furniture .... are you pre vaccing, are you using low moisture, bonnet hwe, encap, ect ect . will you be prspraying, aggitating , if so what with , a brush, a host a rotary,
a little more info , and some may be able to give a reasonable answer.
geoff