Can I get a calculation on my taxes before I file on how much I will receive?

Yes, there is a refund/amount due tracker in TurboTax. It's on the top left hand side of the screen. Click on Show my refund so far. 

If you have questions about why your refund is less than last year, please see the following information:

Although tax law changes lowered the rates for five of seven tax brackets, your refund may not be as big as you expected because less income tax was taken out of your paychecks throughout the year. If you didn't update your W-4 for 2020 or 2019 (most people didn't), it’s highly possible this is why your refund isn’t as large as you expected.

We've got some other possible reasons for a year-over-year refund decrease.

Tip: If your refund is wildly off, you may have mistyped a dollar amount somewhere. An extra digit here, a missing number there, even a misplaced decimal point can have an eye-popping (but easily correctable) effect on your refund.

Changes in your income or tax rate

State and local income tax deduction changes

Losing certain credits or deductions