You can use the IRS calculator to estimate your tax and withholding. Just make sure that when you enter the gain from your house, to subtract the exclusion and only enter the taxable net.
https://www.irs.gov/individuals/tax-withholding-estimator
In general, if you owned and lived in the home for more than two years, and are single, you can exclude the first $250,000 of gain. The rest of the gain will be taxed at 15%, but if your total income (other income plus the taxable part of the gain) is more than $533,000, then the top part of the gain will be taxed at 20%.
If you owned and lived in the home for more than two years, and are married filing jointly, you can exclude the first $500,000 of gain. The rest of the gain will be taxed at 15%, but if your total income (other income plus the taxable part of the gain) is more than $600,000, then the top part of the gain will be taxed at 20%.
