2 notes on this topic.
This is a record of my effort building the R2-D2 in (73508). It has a total 2314 pieces. Finished it is over 31cm (13”) high, 19cm (8”) wide and 15cm (6”) deep.
This is a record of my effort building the LEGO Millenniuum Falcon (75192). It has a total 7541 pieces. Finished it is over 21cm (8”) high, 84cm (33”) long and 56cm (22”) wide.