There are formulas to phase out the tax credit as your income goes up, equations to calculate what expenses you have left after claiming the credit, formulas to apportion a 529 withdrawal between the remaining education expenses and ineligible uses, and then formulas to apportion the ineligible portion between principal and interest.

FORBES: Paying for College: Federal Tax Credits and Deductions

The AOTC may be claimed in the same year that a tax-free distribution is made as long as the same expenses are not used to calculate the tax-free distribution AND the American Opportunity Tax Credit.

FORBES: College Tax Credit: The $2,500 American Opportunity Tax Credit

It is very important to remember that you cannot claim any of the college tax credits, including the AOTC, based on expenses that were used to calculate the tax-free portion of a distribution from a 529 college savings or prepaid plan, or a Coverdell Education Savings Account (ESA).

FORBES: College Tax Credit: The $2,500 American Opportunity Tax Credit

You calculate the deduction based on qualified education expenses you pay for yourself, your spouse, or a dependent.

FORBES: Back to School: Tuition and Fees Deduction

However, I must count different expenses for both s and when I calculate my child care credit, I must subtract the expenses already excluded from my income from my maximum allowable child care credit expenses.

FORBES: Simplifying Child Care Tax Benefits

We used the teams' total expenses in 2010, as reported to the Department of Education, to calculate their spending per game won this year.

FORBES: Best College Football Teams for the Money

You can use money that you borrow in order to calculate the deduction but you cannot claim a deduction or credit based on expenses paid with tax-free scholarship, fellowship, grant, or education savings account funds such as a Coverdell education savings account, tax-free savings bond interest or employer-provided education assistance.

FORBES: Back to School: Tuition and Fees Deduction