We are renovating home to give it a more updated look which includes the staircase. Doing stained square newel post (6.25” wide), stained handrail, and white square balusters. Treads are 10.25”x43.5”. I know the balusters can’t be more than 4” a part. Stair contractor suggested doing 1 3/4” baluster but that seems big to me.

What is the typical size baluster for this size tread and newel post?