Hi,
An ideal situation with 100% efficiency would mean an input current of 2.71A. But this is impractical and in real life the efficiency can be between 70% to 90%.
Assuming 90% input current = 3A
At 80%, 3.39A.
At 70%, 3.87A
So, without knowing your efficiency, the best guess could be ~3.5A.
Hope this helps.
Tahmid.