Laser Pointer Forums - Discuss Laser Pointers | High Power Lasers

Hello, I've resantly built a red 650nm laser using the DDL driver. I have 4xAA powering it and am using 3.3ohm's of resistance on it and was wondering if it would be possible to calculate the power output. I've searched through this site many times looking for a formula to convert ma's to mw's but was unsuccessful. I'd greatly appreciate any help and tips that you can give.