50:1 Oil Mix Ratio Calculator
Calculate the exact amount of 2-stroke oil needed for your gasoline. Perfect for chainsaws, weed eaters, and other small engines.
Engine & Fuel Details
Enter your gasoline amount and desired mix ratio to calculate the exact oil needed
How much gasoline are you mixing?
Choose your preferred measurement unit.
Check your engine’s manual for the manufacturer’s recommended ratio.
Mix Ratio Results
Exact measurements for your 2-stroke fuel
Enter your gasoline amount and mix ratio above, then click Calculate Mix to get the exact 2-stroke oil measurements.
2-Stroke Oil Mix Quick Guide
Use this chart to quickly find out how much oil you need per gallon or liter of gas for common 2-stroke mix ratios.
| Mix Ratio | Oil per Gallon (fl oz) | Oil per Liter (ml) |
|---|---|---|
| 50:1 | 2.6 fl oz | 20 ml |
| 40:1 | 3.2 fl oz | 25 ml |
| 32:1 | 4.0 fl oz | 31.3 ml |
| 24:1 | 5.3 fl oz | 41.7 ml |
2-Stroke Fuel Mix FAQ
Everything you need to know about mixing fuel, protecting your engine, and getting the best performance from your equipment.
A 50:1 mix ratio means 50 parts of gasoline to 1 part of 2-stroke oil. This is the most common ratio for modern 2-stroke engines like chainsaws, string trimmers, and leaf blowers, providing the right balance of lubrication and clean burning.
For a 50:1 mix, you need to add 2.6 fluid ounces (fl oz) of 2-stroke oil to 1 US gallon of gasoline. If you are mixing 1 liter of gas, you need exactly 20 milliliters (ml) of oil.
No, you should never use regular 4-stroke motor oil in a 2-stroke engine. Regular motor oil contains additives designed for a sump system that do not burn cleanly. Using it will cause excessive smoke, spark plug fouling, port clogging, and eventually severe engine damage. Always use oil specifically certified for 2-stroke engines (look for JASO-FD or ISO-L-EGD ratings).
Putting too much oil in a 2-stroke engine can cause a rich fuel mixture, leading to excessive smoke, poor performance, spark plug fouling, and carbon buildup in the exhaust port and muffler. Over time, this can clog the engine and require expensive repairs. Conversely, too little oil will cause insufficient lubrication, leading to rapid engine seizure and catastrophic failure.
Pre-mixed 2-stroke fuel should ideally be used within 30 days. Over time, the gasoline degrades and loses its octane rating, while the oil can separate or settle at the bottom. If you must store it for longer, use a fuel stabilizer, keep it in an approved, tightly sealed container in a cool, dark place, and always shake it vigorously before use.