Recommendations for a voltage regulator?

Hi everyone! I have a breadboard ATmega328 with LEDs that uses 50 mA when awake, and 6.8 uA when sleeping. The chip is programmed to be awake for 2 minutes, and then sleep for 4 hours (240 min). I am planning on using a 7.4v lipo with it, and would like it to run as long as possible (until the battery cuts-off at ~5.8v).

Therefore, I was wondering:

  1. How can I calculate what would the total battery draw be when the chip is awake using a voltage regulator such as one of the following? a. MCP1702 Linear regulator ( b. Pololu D24V5F5 step-down switching regulator (

  2. How can I calculate what the battery draw would be for each regulator when the chip is sleeping?

Any thoughts & suggestions would be great... Thanks!

While the chip is sleeping, the regulator is at least drawing the quiescent current, which for the Pololu board is stated to be 200 uA. Add that to all the other current draws in the circuit.