Be wary of choosing a frame size based on your height. The most important measurement is your inseam length. All people are not created equal. Ten 5'10" tall people could have inseam measurements that vary by several inches.

When I used to fit people for bikes, a general rule of thumb we used was inseam length (crotch to heel) minus 10 inches equals frame size. Your 54cm frame is about 21.25 inches so you're in the ballpark. But as Tom stated, there is no industry standard for measuring frame size. They can be measured to the top of the seat tube, the top of the top tube, or the centerline of the top tube. I've seen all three. So one manufacturer's idea of a 54cm frame could be way different from another's. But then again, for a recreational rider a couple of centimeters is not a deal breaker.

Just keep in mind that your saddle, shoes, cleats (if used) and even pedaling style will all affect your saddle height.