Stair Rise and Run

For safety and ease of use, stairs must comply with specific requirements. The rise and the run must be uniform for all treads in a flight of stairs. For stairs in houses, the minimum run for rectangular stairs is 210 mm (8¼ in.), and the maximum is 355 mm (14 in.). The minimum rise is 125 mm (5 in.), and the maximum is 200 mm (8 in.). The minimum tread depth is 235 mm (9¼ in.), and the maximum is 355 m 13 (15⁄16 in.).

Source : Canada Mortgage and Housing Corporation (CMHC)