your tax bill will be for the whole year and then withhold a portion of that every paycheck so that at the end of the year you have paid enough taxes. If you withhold more than your tax bill, you get a refund when you file your taxes. If you withhold less than your tax bill, you owe when you file your taxes.

But it doesn't change at all what your total tax liability is (unless you incur a penalty for not withholding enough).

So if you want your paychecks to be bigger (by withholding less tax each paycheck), you claim more exemptions on your W4. If you want smaller paychecks and a bigger refund, claim fewer exemptions. You can even select an extra dollar amount to withhold if you want.

I'd recommend targeting for a small refund (<$500) to minimize the amount of your money that the IRS holds without paying you interest.

Here is a good calculator you can use: