I ride comfortably on 57.5 cm to 58 cm center to top steel bikes,

here is a chart to help determine your correct size,relative to traditional steel road bike geometry, ( bike frame size is seat tube  center to top), not the more modern sloping frames.

Determining Your Road Bike Frame Size
Height	Inseam Length	Bike Frame Size
4’10” – 5’1″	25.5” – 27”	46 – 48 cm
5’0″ – 5’3″	26.5″ – 28″	48 – 50 cm
5’2″ – 5’5″	27.5″ – 29″	50 – 52 cm
5’4″ – 5’7″	28.5″ – 30″	52 – 54 cm
5’6″ – 5’9″	29.5″ – 31″	54 – 56 cm
5’8″ – 5’11”	30.5″ – 32″	56 – 58 cm
5’10” – 6’1″	31.5″ – 33″	58 – 60 cm
6’0″ – 6’3″	32.5″ – 34″	60 – 62 cm
6’2″ – 6’5″	34.5″ – 36″	62 – 64 cm