Here is a list of the Halo: Reach ranks and how many cR you need to get them:
- Recruit 0 cR
- Private 7,500 cR
- Corporal 10,000 cR
- Corporal Grade 1 15,000 cR
- Sergeant 20,000 cR
- Sergeant Grade 1 26,250 cR
- Sergeant Grade 2 32,500 cR
- Warrant Officer 45,000 cR
- Warrant Officer Grade 1 78,000 cR
- Warrant Officer Grade 2 111,000 cR
- Warrant Officer Grade 3 144,000 cR
- Captain 210,000 cR
- Captain Grade 1 233,000 cR
- Captain Grade 2 256,000 cR
- Captain Grade 3 279,000 cR
- Major 325,000 cR
- Major Grade 1 350,000 cR
- Major Grade 2 375,000 cR
- Major Grade 3 400,000 cR
- Lt. Colonel 450,000 cR
- Lt. Colonel Grade 1 480,000 cR
- Lt. Colonel Grade 2 510,000 cR
- Lt Colonel Grade 3 540,000 cR
- Commander 600,000 cR
- Commander Grade 1 650,000 cR
- Commander Grade 2 700,000 cR
- Commander Grade 3 750,000 cR
- Colonel 850,000 cR
- Colonel Grade 1 960,000 cR
- Colonel Grade 2 1,070,000 cR
- Colonel Grade 3 1,180,000 cR
- Brigadier 1,400,000 cR
- Brigadier Grade 1 1,520,000 cR
- Brigadier Grade 2 1,640,000 cR
- Brigadier Grade 3 1,760,000 cR
- General 2,000,000 cR
- General Grade 1 2,200,000 cR
- General Grade 2 2,350,000 cR
- General Grade 3 2,500,000 cR
- General Grade 4 2,650,000 cR
- Field Marshall 3,000,000 cR
- Hero 3,700,000 cR
- Legend 4,600,000 cR
- Mythic 5,650,000 cR
- Noble 7,000,000 cR
- Eclipse 8,500,000 cR
- Nova 11,000,000 cR
- ForeRunner 13,000,000 cR
- Reclaimer 16,500,000 cR
- Inheritor 20,000,000 cR