Why is the capital gains amount on my tax form different from Turbo Tax?

It depends. Discrepancies between the capital gains amount on your tax form and TurboTax can arise for several reasons:

1. Data Entry Errors: If information from your financial institution was imported incorrectly or manually entered with mistakes, it could lead to mismatched figures. 
2. Rounding Differences: TurboTax may round numbers differently than the IRS, which can cause small discrepancies.
3. Software Calculations: TurboTax's internal calculations for capital gains tax might differ from IRS methods, especially if there are complex scenarios like long-term vs. short-term gains, which may or may not be accounted for.
4. Capital Loss Carryovers: If you have capital loss carryovers, TurboTax might apply them differently than expected