MY REFUND WAS LESS THAN I EXPECTED
There can be a number of reasons why your refund was less than the amount you expected. First of all, look carefully at your actual tax returns. There is sometimes confusion about the amount of refund to expect when users misinterpret the “summary” they saw in TurboTax. The amount of your refund is on your tax return. Federal refund is on line 35a on Form 1040 State tax forms are all different so we cannot tell you what line to look at on your state form. BUT it is important to actually LOOK at your tax return forms yourself and see the amounts of your tax refunds and/or tax due. A lot of confusion would be avoided by doing that.
Be aware also that your Federal refund and state refund do NOT come together. Federal and state tax returns are processed by two completely separate entities. There is no rule as to which one will come first,
It is also possible that your state reduced your refund for debts owed in your state—if the state reduced your state refund you will receive a letter from the state.
Did you choose to have TT fees deducted from your Federal refund? (Remember that if you did that, you also agreed to an extra refund processing fee of $40 or $45 in CA)
How can I see my TurboTax fees?
https://ttlc.intuit.com/questions/2565973-how-do-i-review-my-fees-in-turbotax-online
What is Refund Processing Service?
https://www.irs.gov/uac/tax-refund-offsets-pay-unpaid-debts
IRS Treasury Offset Program Call Center at 1-800-304-3107
https://www.irs.gov/uac/tax-refund-offsets-pay-unpaid-debts
https://ttlc.intuit.com/community/refunds/help/what-is-a-refund-offset/00/26301
Reduced Refund https://www.irs.gov/taxtopics/tc203
NOTE: You can contact the IRS Treasury Offset Program Call Center at 1-800-304-3107 to ask if they have an offset for you on file. TurboTax would not have that information.
https://turbotax.intuit.com/tax-tips/tax-payments/who-can-garnish-an-income-tax-refund/L7cPPzDyc
What do you mean by "estimated"? Where did you see an estimate of your refund? Your actual federal refund is the amount on line 35a of Form 1040 in the tax return that you filed. That is not an estimate. If you chose the option to have TurboTax fees taken out of your federal refund, then your refund will be reduced by the amount of the TurboTax fees plus a processing fee.
The IRS might have reduced your federal refund. If so, they will send you a letter explaining what they changed. You should get the letter 2 or 3 weeks after you received the federal refund.