Two-Stroke Oil Mix Calculator
Calculate how much two-stroke oil to add to gasoline for common ratios such as 32:1, 40:1, and 50:1. Results are shown in several practical measuring units.
Oil Mix Result
Mixing Instructions
Confirm the required ratio in the equipment manual or on the manufacturer’s label. Using the wrong ratio can cause poor performance or engine damage.
Quick Reference Chart
| Ratio | Oil per 1 US Gallon | Oil per 1 Liter |
|---|---|---|
| 16:1 | 8.00 fl oz | 62.5 mL |
| 20:1 | 6.40 fl oz | 50.0 mL |
| 25:1 | 5.12 fl oz | 40.0 mL |
| 32:1 | 4.00 fl oz | 31.25 mL |
| 40:1 | 3.20 fl oz | 25.0 mL |
| 50:1 | 2.56 fl oz | 20.0 mL |
| 60:1 | 2.13 fl oz | 16.67 mL |
| 80:1 | 1.60 fl oz | 12.5 mL |
| 100:1 | 1.28 fl oz | 10.0 mL |
How the Calculation Works
A ratio such as 50:1 means 50 equal parts gasoline for every 1 part oil. The calculator converts the gasoline amount to a common volume and divides it by the first number in the ratio.
Oil volume = gasoline volume ÷ ratio
One US gallon contains 128 US fluid ounces. One liter contains 1,000 milliliters.
Mixing Tips
- Use fresh gasoline and oil intended for two-stroke engines.
- Measure the oil rather than estimating by eye.
- Add part of the gasoline to an approved fuel container, add the measured oil, mix thoroughly, and then add the remaining gasoline.
- Label fuel containers with the ratio and mixing date.
- Do not assume every two-stroke engine uses the same ratio.
This calculator performs volume conversions only. Always use the fuel type, oil type, and mixture ratio specified by the equipment manufacturer. Requirements can differ by engine, model, oil product, operating conditions, and break-in procedure.