While some of it is going to be using your best guess and estimates (you can reference prior years) - if you need to estimate the amount of taxes you may owe, then you have two options that TurboTax can help you with -
The best option is to complete as much of the return as possible to get the most accurate idea of if/how much taxes you might owe. Then, file for an extension and pay the amount of taxes due to avoid interest.
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