If your refund is much lower than your estimated tax savings, there are important reasons why. Your estimated tax savings is the money you’ll get back from the government at tax time as a bill reduction. When you file your return, those tax savings are used to reduce the amount of money you’re required to pay taxes on.
For example, if you have $10,000 in income and $2,000 in write-offs, then you only have to pay taxes on $8,000. If you don't owe the IRS any money before you include your write-offs, you’ll likely receive a refund.