My wife has cashed out her 401k after quiting previous job.20% fed and 2% state(ca).should we expect to pay more taxes next tax season?if so what % can we expect?

What about the 10 percent penalty for early withdraw? ( depends on her age)

But the withholding is merely an estimated tax, just like your weekly check, so when you file your taxes and show this as income, and the tax as taxes with held. So if your total tax due may be less or may be more, depending upon your status and other deductions when you file your taxes