Here are the ranks and how many posts you need to reach each rank.Good luck
E1 - Private - 0 posts
E2 - Private - 1 posts
E3 - Private First Class - 25 posts
E4 - Specialist - 50 posts
E4 - Corporal - 75 posts
E5 - Sergeant - 100 posts
E6 - Staff Sergeant - 125 posts
E7 - Sergeant First Class - 150 posts
E8 - Master Sergeant - 175 posts
E8 - First Sergeant - 200 posts
E9 - Sergeant Major of the Army - 225 posts
E9 - Command Sergeant Major - 250 posts
E9 - Sergeant Major of the Army - 300 posts
W1 - Warrant Officer 1 - 400 posts
W2 - Chief Warrant Officer 2 - 475 posts
W3 - Chief Warrant Officer 3 - 550 posts
W4 - Chief Warrant Officer 4 - 625 posts
W5 - Master Warrant Officer 5 - 700 posts
O1 - Second Lieutenant - 800 posts
O2 - First Lieutenant - 950 posts
O3 - Captain - 1000 posts
O4 - Major - 1050 posts
O5 - Lieutenant Colonel - 1100 posts
O6 - Colonel - 1150 posts
O7 - Brigadier General - 1200 posts
O8 - Major General - 1250 posts
O9 - Lieutenant General - 1300 posts
O10 - General - 1500 posts