Listed gear-ratio data for 2009 Mercury 225 HP DFI / OptiMax outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2009 Mercury 225 HP DFI / OptiMax
Listed ratio values: 1.75:1
| Model | Gear ratio |
|---|---|
| 1998-2012 | 1.75:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.