This question is impossible to answer due to lack of information ... so some general stats ... the distribution will be taxed by the feds as ordinary income at whatever marginal rate the income puts you and if you are under the age of 59.5 there will also be a 10% penalty added plus any state taxes applicable.
You could roll the 401K to an IRA and then take distributions as needed instead of all at once to spread the tax burden over more than one tax year. This is something you need to compute before you take the first dollar so you know exactly how this will affect you.
Try these tools:
http://www.irs.gov/Individuals/IRS-Withholding-Calculator
https://turbotax.intuit.com/tax-tools
http://turbotax.intuit.com/tax-tools/calculators/taxcaster
