for SFO's depends on a few things. Deductions can be different for each person: some contribute more to their pension, family medical insurance, BALPA subs, recreation clubs, share save etc.
PP10 SFO 777 take home is around £4000 pm month for a full months work - around 86-92 hours. Obviously less for leave months as we have quite a lot of variable pay compared to other airlines although a lot less than it used to be.
At the moment a lot of overtime available due short crewing so if you wanna do extra you can and earn a lot more.