2 new tyres required

[tangoman]

This isn't the usual quwation but advice needed.
Currently driving round on standard 215/50 17 tyres all round.
Need 2 tyres on the front but I was looking to go 1 size up to 225s.
The question is--Do I fit the new tyres on the front/or rear or would the advice be 4 tyres. Rears are currently about 4-5mm.

[lee gsi]

I fitted the wider ones to the rear than when the others needed changing bought the matching size.