How to Check If You Are Running Sade Sati
Find your Moon sign first
Sade sati is calculated from the Moon, not the sun sign used in newspaper columns. You need your birth time to establish it accurately.
Then check Saturn
If Saturn currently occupies the twelfth, first or second sign counted from your Moon, you are within the period. Each phase runs roughly two and a half years.
Severity depends on your chart
Saturn's strength in your birth chart, and whether it is a benefic for your lagna, matter far more than the transit itself. Two people in identical sade sati phases can have entirely different experiences.
Full Kundli Analysis
A complete read of your birth chart — dasha periods, key yogas, doshas, and the phases coming up over the next three years.