Are you married? DId you *and* your spouse live in the property as your primary residence for "at least" 2 of the last five years, counting backwards from the closing date you sold it? That comes to 731 days of the last 1826 days you owned it, and the day count does not include the closing date of your sale.
Basically, if *bith* you and your spouse lived in the property as your primary residence for at least 731 days of the last 1826 days you owned it, then you can exclude a maximum of $500,000 gain from taxation.
If only you lived in it at your primary residence for at least 731 days of the last 1826 days you owned it, then you can exclude $250,000 of your gain from taxation. It also matters what the classification of the property was when you sold it - rental or personal use/primary residence.
