When you measure a bike you have to look at the seat tube height and the top tube length be that real or virtual... compact frames with sloping top tubes need to be measured differently than traditional frames.

I am 176cm tall, have a 82.5cm / 32.5 inch riding inseam, and am quite comfortable with a saddle to bar reach of 80-82 cm which I could not get in a 48cm frame without a radically long stem (120-130mm) and this would just mess up the geometry of the bike.

My smallest bike is a 52cm / 20 inch road bike with traditional geometry and a 52cm top tube and 100 mm stem... it is a very aggressive set up with a good deal of drop while my 55cm road bike has an 80mm stem and a little less drop which is better for longer distances and climbing.

My hybrid and mtb are also 52 cm frames but with their compact geometry ride out like 55cm frames which is the same as all my other bikes.

I have been fitted professionally and also do a lot of bike fitting and know for me, a 52-55cm frame is optimal... have ridden 56-58 cm frames and have been pretty comfy although this rates a shorter stem and I am missing some needed clearance on stand over.

I am gonna say that a 48cm frame is too small for you in both aspects unless you have inordinately short legs for your height or really short arms... if you have average proportions I would be sending you out on a 21 or 22 inch frame.