The "Taxcaster" tool is here: <a rel="nofollow" target="_blank" href="
https://turbotax.intuit.com/tax-tools/calculators/taxcaster/?s=1">https://turbotax.intuit.com/tax-to...>
Underpayment penalty is due if both of the following apply:
- 1. You to owe at least $1,000 at tax time, after subtracting your withholding and credits.
- 2. Your withholding and credits was less than the smaller of: 90% of the tax to be shown on your current year’s tax return, or 100% of the tax shown on your prior year’s tax return.
The underpayment penalty is currently about 5.5% interest rate
