Inside the house - 8 chairs around the dining table (hardly used, except at Christmas), 4 chairs at the breakfast bar, 3 office chairs (me, Mrs C, Miss C), 1 beanbag for Miss C (me and Mrs C can't go that low any longer), Daddies armchair, Mummies armchair, 2 sofas (not counted for the purpose of this survey), and a small wooden desk and chair set that Miss C is not willing to let go yet (she's 9 and it fits a 4/5 year old).
Outside - a teak table with 4 chairs and 2 upholstered chairs with sofa (sofa not counted).
So, 25 chairs for three of us in a modest 3-bedroom house and garden.