I currently have 6 allowances on w4. I'm getting a $24,000/yr raise..should i change my allowances?

[amderby22]

I currently put 10% into my 401k and was planning on doing the same with this new job.

[DoninGA]

Use the W-4 calculator here - https://turbotax.intuit.com/tax-tools/calculators/w4/

Or the IRS W-4 calculator here - https://www.irs.gov/individuals/irs-withholding-calculator

[SweetieJean]

Be sure to check with your new employer re (1) the waiting period for you to join their 401(k), and (2) the maximum annual contribution allowed by the plan.

[dmertz]

TurboTax's W-4 calculator has not yet been updated to work for 2016.  If you do try you use it,  until it is updated you must indicate your age as of December 31, *2016* (not 2015) and you must answer the question that asks the date on which you will receive your next paycheck with a date in 2015 instead of 2016 (as if the current year is 2015).