The gain is measured from the property's fair market value on the date of death, sometimes called the deemed disposition, not from what the original owner originally paid for it, and only 50 percent of that gain is taxable, so a proper date-of-death valuation matters for calculating any tax owed.
If you moved into the inherited home and it became your principal residence before selling, only the portion of the gain from the date of death to when it became your principal residence is generally taxable, which makes the timeline of your own occupancy relevant too.
This is general information, not tax advice, and an accountant should confirm the numbers for your specific estate. Get your hand-reviewed valuation from Joel Dyck.