Listed gear-ratio data for 2020 Tohatsu 9.9 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2020 Tohatsu 9.9 HP
Listed ratio values: 1.85:1, 2.15:1
| Model | Gear ratio |
|---|---|
| M9.9D2 | 1.85:1 |
| MFS9.9E | 2.15:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.