Fuel Oil Mix Calculator
Calculate the exact amount of 2-stroke oil needed for your gas mixture.
Result:
Understanding 2-Stroke Fuel Ratios
Whether you are operating a chainsaw, string trimmer, outboard motor, or a vintage moped, getting the fuel to oil mixture correct is critical for engine longevity. Two-stroke (2-cycle) engines do not have a dedicated oil reservoir like a car; instead, they rely on oil mixed directly into the gasoline to lubricate the cylinder, piston, and crankshaft.
How to Use the Fuel Mix Calculator
- Select your unit: Choose between Liters or US Gallons.
- Input fuel quantity: Enter how much gasoline you have in your gas can.
- Enter the ratio: This is usually found on the fuel cap or in the user manual. A "50:1" ratio means 50 parts gasoline to 1 part oil. You only need to enter the "50" in the ratio box.
- Calculate: The tool will tell you exactly how many milliliters (for liters) or fluid ounces (for gallons) of 2-cycle oil to add.
Common Fuel Mix Ratios
| Ratio | Per 1 Gallon (US) | Per 5 Liters |
|---|---|---|
| 32:1 | 4.0 fl. oz. | 156.25 mL |
| 40:1 | 3.2 fl. oz. | 125.00 mL |
| 50:1 | 2.6 fl. oz. | 100.00 mL |
The Dangers of Incorrect Mixing
Too much oil (Rich Mix): While "safe" for the metal components, excess oil causes heavy smoke, carbon buildup on the spark plug (fouling), and clogged exhaust ports, leading to power loss.
Too little oil (Lean Mix): This is catastrophic. Without enough lubrication, the friction between the piston and cylinder wall creates extreme heat, causing the engine to "seize" or weld itself together, usually resulting in a total engine loss.
Pro Tips for Mixing Fuel
- Always use fresh gasoline (ethanol-free is preferred for small engines).
- Use a high-quality TC-W3 or JASO FD rated oil depending on your equipment requirements.
- Pour the oil into the container first, then add the gasoline to ensure a thorough mix.
- Shake the container vigorously before every use, as oil can settle over time.