Essentially much the same as today - 3 classes - upper, middle, working with 3 subclasses for each.

However the middle class was much smaller than today, and the only way to reach it's upper echelons for a man was through ownership of a manufacturing or shipping business.

The upper class was reserved for those who had been educated in one of the 'public' (private) schools, so the only way in was to have been educated this way.

In 'Down and out in London', which is admittedly 30-50 years after the Victorian times, Orwell notes that the middle class church going types who run the homeless shelters call him Sir like he's a hotel guest, whereas all the working class bums get nothing of the sort, but this would be typical of Britain from industrial revolution to ww2 - social hierarchy and income/ownership don't correspond asmuch as one would expect until you get to the very top and bottom of the heirarachy, so long as you were 'brought up properly'.

Therefore there were quite a few mill owning northerners who were quite rich but socially not of the same status of much poorer men who had been well educated. There was little opportunity for them to climb classes, but their sons and daughters could gain much easier acceptance. For working class men to climb into the middle class, the only option was a long stint in the army hoping to reach the lower officer ranks, or join the clergy.

For women it was also possible to marry into class, although the liklihood of this happening was low and tended more to be from a single subclass or two below, anything else would not be proper. For a working class woman to join the middle classes of her own accord, Nursing and particularly becoming a ladies Maid were attractive options. Ladies Maids were usually required to dress and look after the chambers of richer women, and were not expected to do the sort of work which would get ones hands dirty. As such they were a sort of fast track to the very middle class housekeeper position.