New Job and W4 question

[sopsyched]

Hey ladies.... So I recently started a new job (Jan 7th). Normally I just take 3 deductions: one for me and each of my children. However, this time, I actually filled out the W4 worksheet, and it told me I qualified for 10 deductions... so I went with that, thinking I would just receive a much lower tax refund next year. I wanted to double check the accuracy of this though, so I googled a withholding calculator. It told me I would end up owing like 3k next year? Can anyone tell me if this is true, and how I can accurately find out my tax liability?
If I need to adjust my withholdings I'd rather do it now, than get a surprise later.
Some info: I work for a local government, so FICA is not taken from my check. My gross is a little above 50K. I file head of household, have two kids under 10, and also pay for their before and after care. Can anybody point me in the right direction?

[mrsfarmer]

If you go to paycheckcity.com, they have a W4 calculator.

[sopsyched]

thanks ms farmer, I did that, and it said I qualified for 10...so I guess I should just relax?

[LoveTrains]

Has your income changed a lot since last year?

Have you done your 2012 taxes yet?

I suggest looking at the line on your 1040 that has the amount that you owe (total for the year). Then divide that by the number of times you get paid per year. Now you have an approximate idea of how much you want withheld per check. Now compare with your last stub to see how much was withheld. Was it more? Less? You can adjust from there.