Just for reference, Halo Reach Rank and the amount of cR needed to hit that rank
Recruit 0cR
Private 7,500cR
Corporal 10,000cR
Corporal Grade 1 15,000cR
Sergeant 20,000cR
Sergeant Grade 1 26,250cR
Sergeant Grade 2 32,500cR
Warrant Officer 45,000cR
Warrant Officer Grade 1 78,000cR
Warrant Officer Grade 2 111,000cR
Warrant Officer Grade 3 144,000cR
Captain 210,000cR
Captain Grade 1 233,000cR
Captain Grade 2 256,000cR
Captain Grade 3 279,000cR
Major 325,000cR
Major Grade 1 350,000cR
Major Grade 2 375,000cR
Major Grade 3 400,000cR
Lt Colonel 450,000cR
Lt Colonel Grade 1 480,000cR
Lt Colonel Grade 2 510,000cR
Lt Colonel Grade 3 540,000cR
Commander 600,000cR
Commander Grade 1 650,000cR
Commander Grade 2 700,000cR
Commander Grade 3 750,000cR
Colonel 850,000cR
Colonel Grade 1 960,000cR
Colonel Grade 2 1,070,000cR
Colonel Grade 3 1,180,000cR
Brigadier 1,400,000cR
Brigadier Grade 1 1,520,000cR
Brigadier Grade 2 1,640,000cR
Brigadier Grade 3 1,760,000cR
General 2,000,000cR
General Grade 1 2,200,000cR
general Grade 2 2,350,000cR
General Grade 3 2,500,000cR
General Grade 4 2,650,000cR
Field Marshall 3,000,000cR
Hero 3,700,000cR
Legend 4,600,000cR
Mythic 5,650,000cR
Noble 7,000,000cR
Eclipse 8,500,000cR
Nova 11,000,000cR
Forerunner 13,000,000cR
Reclaimer 16,500,000cR
Inheritor 20,000,000cR