Attiny and cr2032 battery power

Hello guys. How long can attiny85 last on a cr2032 3.3v battery with no sleep mode, no low power mode, or any other components attached, and the chip is just directly connected to the battery. A straight 3.3 volts directly to the chip.

A rough estimate of the operating hours = (battery capacity in mAh)/(average circuit current draw in mA)