I'm 30 weeks pregnant with twins at what point do they become capable of surviving outside the womb?

Depends on hospital: That's a tricky a question because if you expect for no interventions to be needed then standard delivery of twins is at 37-38 weeks but even then twins can have slower lung maturity than their single pregnancy counterparts and I would always want neonatal pediatricians around for support. This is also dependent on their placenta and sacs. If with specialist care, sometimes earlier delivery OK.