A student loan deduction is a deduction, not a credit. It does not reduce your tax dollar for dollar. It reduces your tax by reducing your taxable income. The maximum benefit you get from a deduction is the amount of the deduction times your marginal tax rate. For example, if you are in the 25% marginal tax bracket, a $1,000 deduction reduces your tax by, at most, $250.
The maximum student loan interest deduction that you can claim is $2,500 per tax return.