Don't forget you can increase your cost basis by any costs you paid for permanent improvements (new roof, new furnace, carpet or hardwood floors, kitchen remodel, etc.). This means items attached to or part of the house--a built-in stove would count but not a freestanding range. Also, you can only include costs for items that are still part of the house. For example, if you replaced the roof in 1990 and again in 2020, you can only include the cost of the 2020 roof.
You must reduce the cost basis by any depreciation you claimed or could have claimed for business use of the home, such as as a rental, or home office deduction, or home daycare.
You can also adjust the selling price by certain closing costs, see publication 523.
https://www.irs.gov/forms-pubs/about-publication-523
Then, your capital gains is simply the net selling price minus the cost basis. How much tax you will pay depends on many other factors, most importantly, have you lived in home as your main home for part or all of the time since you inherited it?
