Concerning all possible endings and what you need, according to this site, justpushstart.
Collector’s Base Saved
Readiness Rating < 1750 – Earth is destroyed regardless of whatever decisions you made. Readiness Rating 1750 – Choose to Save the Reapers and the Earth will be saved. Readiness Rating 2050 – Choose to become a Reaper and the Earth will be saved. Readiness Rating 2350 – Choose to destroy the Repears and the Earth will be somewhat destroyed Readiness Rating 2650 – Choose to destroy the Reapers and Earth is destroyed. Readiness Rating 2800 – Earth and the Galaxy will be saved once you’re able to create synergy Readiness Rating 4000 – Choose to destroy the Reapers and Save Anderson to see Shepard lives. Readiness Rating 5000 – Choose to destroy the reapers and not Save Anderson to see Shepard lives.
Collector’s Base Destroyed
Readiness Rating < 1750 – Earth is destroyed regardless of whatever decisions you made. Readiness Rating 1750 – Choose to become a Reaper and the Earth will be destroyed. Readiness Rating 1900 – Choose to destroy the Repears and the Earth will be somewhat destroyed Readiness Rating 2350 – Choose to become a Reaper and the Earth will be saved. Readiness Rating 2650 – Choose to destroy the Reapers and Earth will be saved. Readiness Rating 2800 – Earth and the Galaxy will be saved once you’re able to create synergy Readiness Rating 4000 – Choose to destroy the Reapers and Save Anderson to see Shepard lives. Readiness Rating 5000 – Choose to destroy the reapers and not Save Anderson to see Shepard lives.
Thought this would help. (edit link would not work)