Check out How to get your seat height right - BikeRadar for a variety of ways to set your saddle height. The bottom line, if there is one, is that there is no exact correct height. Too high is fairly easy; you'll have to rock back and forth to get to the pedal. Too low? Watch some 14 year old kid on a BMX bike. There is no too low but on a road bike going lower and lower decreases your efficiency but a somewhat lower saddle puts you a bit more upright so experienced fitters will tend to set old people and newbies a bit lower than they would a racer. Going a bit lower also moves you forward which can be a help or hindrance depending on your bike fit. You clearly are in the ball park so your height is absolutely a reasonable one that you should feel free to use for quite a while, raising or lowering it a bit here or there as you wish but not a lot in either direction. Saddle height for a non racer isn't a really critical thing within a cm plus or minus of OK; certainly not as critical as fore-aft position.