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It depends on whether the home was your main residence for two of the last 5 years, if the home was used as a rental property during any of the year in which you owned the home, your filing status, and your other income.
If the home was your main residence, you file married joint, and there was no use as a rental, the taxable gain would be 511,000 dollars (1.5 M - 486k - 500k home sale exclusion = 511k taxable). The gains rate will be 23.8% on a gain this large. The tax would be roughly 122k.
If any of these factors are different, the tax result will be higher.
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