| State | Date | Delegates | Romney | Santorum | Gingrich | Paul | Delegate Allocation | Open/Closed | |
| RCP Total | - | 2,286 | 989 | 259 | 141 | 108 | - | - | |
| Iowa | Jan 3 | 28 | 6 | 7 | 0 | 1 | Non-Binding Caucus | Closed | |
| New Hampshire | Jan 10 | 12* | 7 | 0 | 0 | 3 | Proportional Primary | Open | |
| South Carolina | Jan 21 | 25* | 2 | 0 | 23 | 0 | Winner Take All Primary1 | Open | |
| Florida | Jan 31 | 50* | 50 | 0 | 0 | 0 | Winner Take All Primary | Closed | |
| Nevada | Feb 4 | 28 | 14 | 3 | 6 | 5 | Proportional Caucus1 | Closed | |
| Minnesota | Feb 7 | 40 | 2 | 12 | 1 | 24 | Non-Binding Caucus | Open | |
| Colorado | Feb 7 | 36 | 19 | 6 | 2 | 3 | Non-Binding Caucus | Closed | |
| Maine | Feb 11 | 24 | 2 | 0 | 0 | 21 | Non-Binding Caucus | Closed | |
| Michigan | Feb 28 | 30* | 16 | 14 | 0 | 0 | Hybrid Primary2 | Closed | |
| Arizona | Feb 28 | 29* | 29 | 0 | 0 | 0 | Winner Take All Primary | Closed | |
| Wyoming | Feb 29 | 29 | 22 | 2 | 0 | 1 | Non-Binding Caucus | Closed | |
| Washington | Mar 3 | 43 | 25 | 7 | 0 | 8 | Non-Binding Caucus | Closed | |
| Georgia | Mar 6 | 76 | 19 | 3 | 52 | 0 | Proportional Primary1 | Open | |
| Ohio | Mar 6 | 66 | 38 | 21 | 0 | 0 | Proportional Primary1,3 | Open | |
| Tennessee | Mar 6 | 58 | 16 | 29 | 10 | 0 | Proportional Primary1,3 | Open | |
| Virginia | Mar 6 | 49 | 43 | 0 | 0 | 3 | Hybrid Primary2,3 | Open | |
| Oklahoma | Mar 6 | 43 | 13 | 14 | 13 | 0 | Proportional Primary1,3 | Closed | |
| Massachusetts | Mar 6 | 41 | 38 | 0 | 0 | 0 | Proportional Primary1 | Open | |
| Idaho | Mar 6 | 32 | 32 | 0 | 0 | 0 | Proportional Caucus3 | Closed | |
| North Dakota | Mar 6 | 28 | 20 | 6 | 0 | 2 | Non-Binding Caucus | Closed | |
| Alaska | Mar 6 | 27 | 8 | 8 | 2 | 6 | Proportional Caucus | Closed | |
| Vermont | Mar 6 | 17 | 9 | 4 | 0 | 4 | Hybrid Primary2 | Open | |
| Kansas | Mar 10 | 40 | 7 | 33 | 0 | 0 | Hybrid Primary2 | Closed | |
| Guam | Mar 10 | 9 | 6 | 0 | 0 | 0 | Non-Binding Caucus | Closed | |
| Northern Marianas | Mar 10 | 9 | 6 | 0 | 0 | 0 | Non-Binding Caucus | Closed | |
| Virgin Islands | Mar 10 | 9 | 4 | 0 | 0 | 1 | Non-Binding Caucus | Closed | |
| Alabama | Mar 13 | 50 | 11 | 22 | 12 | 0 | Proportional Primary3 | Open | |
| Mississippi | Mar 13 | 40 | 12 | 13 | 12 | 0 | Proportional Primary1 | Open | |
| Hawaii | Mar 13 | 20 | 9 | 5 | 0 | 3 | Proportional Caucus1 | Closed | |
| American Samoa | Mar 13 | 9 | 9 | 0 | 0 | 0 | Proportional Caucus | Open | |
| Puerto Rico | Mar 18 | 23 | 20 | 0 | 0 | 0 | Proportional Primary3 | Open | |
| Illinois | Mar 20 | 69 | 42 | 12 | 0 | 0 | Direct Election | Open | |
| Louisiana | Mar 24 | 46 | 5 | 10 | 0 | 0 | Proportional Primary1 | Closed | |
| Wisconsin | Apr 3 | 42 | 33 | 9 | 0 | 0 | Winner Take All Primary1 | Open | |
| Maryland | Apr 3 | 37 | 37 | 0 | 0 | 0 | Winner Take All Primary1 | Closed | |
| District of Columbia | Apr 3 | 19 | 16 | 0 | 0 | 0 | Winner Take All Primary | Closed | |
| Missouri | Apr 21 | 52 | 12 | 7 | 1 | 4 | Non-Binding Caucus | Open | |
| New York | Apr 24 | 95 | 92 | 0 | 0 | 0 | Proportional Primary3 | Closed | |
| Pennsylvania | Apr 24 | 72 | 27 | 3 | 3 | 5 | Direct Election | Closed | |
| Connecticut | Apr 24 | 28 | 25 | 0 | 0 | 0 | Hybrid Primary2,3 | Closed | |
| Rhode Island | Apr 24 | 19 | 12 | 0 | 0 | 4 | Proportional Primary | Open | |
| Delaware | Apr 24 | 17 | 17 | 0 | 0 | 0 | Winner Take All Primary | Closed | |
| North Carolina | May 8 | 55 | 36 | 6 | 4 | 6 | Proportional Primary | Open | |
| Indiana | May 8 | 46 | 27 | 0 | 0 | 0 | Hybrid Primary/Caucus1 | Open | |
| West Virginia | May 8 | 31 | 21 | 2 | 0 | 0 | Direct Election | Open | |
| Nebraska | May 15 | 35 | - | - | - | - | Non-Binding Primary | Open | |
| Oregon | May 15 | 28 | 19 | 1 | 0 | 3 | Proportional Primary1 | Closed | |
| Kentucky | May 22 | 45 | - | - | - | - | Proportional Primary1 | Closed | |
| Arkansas | May 22 | 36 | - | - | - | - | Proportional Primary | Open | |
| Texas | May 29 | 155 | - | - | - | - | Proportional Primary1 | Open | |
| California | Jun 5 | 172 | - | - | - | - | Winner Take All Primary1 | Closed | |
| New Jersey | Jun 5 | 50 | - | - | - | - | Winner Take All Primary1 | Open | |
| South Dakota | Jun 5 | 28 | - | - | - | - | Proportional Primary | Closed | |
| Montana | Jun 5 | 26 | - | - | - | - | Non-Binding Primary | Closed | |
| New Mexico | Jun 5 | 23 | - | - | - | - | Proportional Primary | Closed | |
| Utah | Jun 26 | 40 | - | - | - | - | Winner Take All Primary | Open | |
| Unpledged RNC | - | 0 | 54 | 0 | 0 | 1 | Open |
1 Delegates are awarded by district and statewide
2 Some delegates awarded by district and statewide, some proportionately, some winner-take-all
3 Election becomes winner-take-all if a candidate meets a certain threshold (usually 50%)
* States have been penalized half their delegates