Starley's Rover was 40 x 20 using a 26" wheel. 52", which was the most popular size Ordinary.
I set up my Sturmey 3 speed bike so middle gear is 52". 44 x 22 to a 26" wheel. 3rd gear is 69". The bike weighs 32 lb, so the suitable Fixie gear is half way between 2nd and 3rd = 61".
In 1937, Claude Butler launched the 'Tour de Engleterre', the first production 531 bike. It had a Simplex Champion du Monde Pro' 3 speed derailleur. CB would gear the bike to the customer's spec. My uncle John rode in the RAF team, and his spec was 48 chainring, with the middle cog 24. This was 52". Climbing cog was 28, because the bike weighed 22 lb. Speed cog was 16, giving 78".
For a bike of 22 lb, the fixie gear I would fit will be 65".