Following on from chat with friend...
We're both single and childfree with similar basic outgoings (Live in a northern city, my mortgage is £550 pcm, her rent is £600 pcm).
We have very different ideas of what minimum take home needs to be for a comfortable life. By 'comfortable' we're meaning enough to not worry about bills, have a couple nights out a week (say 1 meal but somewhere 'chainy' not expensive, and 1 night out for a few drinks). Maybe a couple of weekends away, but not expensive holidays. To dress nicely but high street.
Both work full time, in a 2 bed flat, and 1 bed flat respectively so similar bills... assume debt free.
I won't say what I think as don't want to sway the responses :)