How do I know if it's better for my wife and I to file separately or jointly?

If you are using TurboTax Online, you would have to create two "dummy" accounts and compete a Married Filing Separately income tax returns for each of you and compare them to your Married Filing Jointly income tax accounts. Remember, you do not pay for tax returns unless you file them.

Generally, filing jointly will give you a bigger refund or less taxes due. See Is it better for a married couple to file jointly or separately?

To create other TurboTax accounts:

1. Sign out of TurboTax Online.
2. Select the TurboTax Online product you want to use for the second return and proceed.
3. On the Create your account screen, set up a new login for the second return.
   
   • You can reuse your email address if you want to receive e-file notifications for the second return.
   • Up to 5 accounts can be tied to the same email address.
4. After you've created the new account, you can start working on the second return.

Tip: If you're preparing multiple returns for family members, it's more economical to switch to the TurboTax CD/Download software, which lets you e-file up to 5 federal returns at no additional cost. More info

If you are using TurboTax CD\Download:  How can we compare married filing jointly with married filing separately?