A treaty ratio for separate battlecruiser tonnage

If the Washington or London treaties separated battlecruiser tonnage from battleships, what ratio might they use?

Probably about one part battlecruisers to three parts battleships, similar to the carrier allowance, producing a rough 3-1-1 split among battleships, battlecruisers, and carriers.

The estimate starts from the treaty relationship between aircraft-carrier and battleship tonnage. A separately recognized battlecruiser category might receive a broadly similar one-to-three allowance against battleships. In a simplified five-part capital-ship total, three parts would go to battleships, one to battlecruisers, and one to carriers. Treaty categories could therefore shape fleet composition before designers chose individual ships.