The start of the 2012 Blackmores Sydney Marathon
For slower runners, joggers or walkers it is important to be in the correct starting group. There are three groups in each race all seeded according to expected finish time. All prams and wheelchairs (except racing chairs in the marathon) must be in the final start group (C Group). Your time will not be affected in any way as the timing chip will only record your time from when you cross the start mats to the finish line mats. This will allow you to enjoy the event at your own pace and provide you with the best possible end result.
| Start Group | Estimated Finish Time | First | Last |
| Elite / Preferred | Male - sub 2 h 50m Female - sub 3h 15m | A1 | A150 |
| A Group | Under 3h 45m | A10000 | A11200 |
| B Group | Between 3h 45m to 4h 30m | B13000 | B15000 |
| C Group | Over 4h 30m | C16000 | C17050 |
| Start Group | Estimated Finish Time | First | Last |
| Elite / Preferred | Male - sub 75m Female - sub 85m | A300 | A399 |
| A Group | Under 1h 55m | A400 | A3499 |
| B Group | Between 1h 55m - 2h 15m | B3500 | B6699 |
| C Group | Over 2h 15m | C7000 | C9699 |
| Start Group | Estimated Finish Time | First | Last |
| Elite / Preferred | Male - sub 35m Female - sub 40m | A25000 | A25100 |
| A Group | Under 50m | A26000 | A31499 |
| B Group | Between 50m - 60m | B32000 | B37499 |
| C Group | Over 60m (inc Prams) | C38000 | C43499 |
| Start Group | Estimated Finish Time | First | Last |
| A Group | Under 25m | A18000 | A18999 |
| B Group | Between 25m - 40m | B19000 | B21999 |
| C Group | Over 40m (inc Prams) | C22000 | C24999 |