2 Cycle Oil Mix Ratio Calculator
Calculate the exact amount of 2-cycle oil needed for your gasoline. Use our mix ratio chart and calculator for 50:1, 40:1, 32:1, and custom 2-stroke engine fuel mixes.
Fuel & Equipment Details
Enter your gasoline amount and desired mix ratio to calculate the exact amount of 2-cycle oil needed.
The total amount of gasoline you want to mix.
Check your equipment’s manual for the manufacturer’s recommended ratio.
Mix Ratio Results
Exact measurements for your 2-stroke fuel mixture
Enter your gasoline amount and desired mix ratio above, then click Calculate Mix Ratio to see the exact amount of 2-cycle oil needed.
2 Cycle Oil Mix Ratio Chart
Use this chart to quickly determine how much 2-cycle oil to add per gallon of gasoline based on your equipment’s required ratio.
| Mix Ratio | Oil per 1 Gallon (fl oz) | Oil per 1 Gallon (ml) | Common Equipment |
|---|---|---|---|
| 50:1 | 2.6 fl oz | 76 ml | Modern chainsaws, string trimmers |
| 40:1 | 3.2 fl oz | 95 ml | Some chainsaws, brush cutters |
| 32:1 | 4.0 fl oz | 118 ml | Older chainsaws, leaf blowers |
| 24:1 | 5.3 fl oz | 157 ml | Heavy-duty equipment, older models |
| 16:1 | 8.0 fl oz | 236 ml | Very old equipment, high load |
2-Stroke Engine FAQ
Everything you need to know about mixing 2-cycle fuel, choosing the right oil, and maintaining your small engines.
For most modern handheld 2-stroke equipment like chainsaws, string trimmers, and leaf blowers, the most common mix ratio is 50:1 (50 parts gasoline to 1 part oil). Always check your specific equipment’s manual, as older models may require 40:1 or 32:1.
Since there are 128 fluid ounces in a US gallon, you divide 128 by the ratio number. For example, for a 50:1 mix, divide 128 by 50, which equals 2.56 fluid ounces of oil per gallon of gas. For a 40:1 mix, divide 128 by 40, which equals 3.2 fluid ounces per gallon.
Adding too much oil (a richer mix, like 32:1 instead of 50:1) can cause the engine to smoke excessively, foul the spark plug, and leave carbon deposits in the exhaust port and muffler. While it won’t immediately destroy the engine, it reduces performance and requires more frequent maintenance.
Running a 2-cycle engine with too little oil (a lean mix, like 60:1 instead of 50:1) is extremely dangerous. The oil lubricates the piston and cylinder; without enough of it, the engine will overheat, score the cylinder walls, and can seize completely in a matter of minutes, causing catastrophic and irreversible damage.
No, you should never use regular 4-stroke motor oil in a 2-cycle engine. Regular motor oil is not designed to be burned and will leave heavy ash deposits that can destroy the engine. You must use a dedicated 2-cycle oil (often labeled as TC-W3 for water-cooled or JASO-FD/ISO-L-EGD for air-cooled engines) that is designed to burn cleanly.