How large might capital ships have grown without treaties?

If naval treaties and other attempts to stop the technology race had failed, how large might battleships and battlecruisers have become by 1939?

Roughly 70,000 tons is a plausible late-1930s size.

An unconstrained interwar capital-ship race could plausibly have produced ships of roughly 70,000 tons by 1939. This is estimated as a likely plateau, with displacement still subject to practical limits. That scale provides a comparison between the historical treaty fleet and contemporary maximum-battleship studies.