50 to 1 Fuel Mix Calculator
Instantly calculate the exact amount of 2-stroke oil needed for your fuel mix. Free, accurate ratio calculator for chainsaws, weed eaters, and leaf blowers.
Calculate Your Fuel Mix
Enter your desired fuel volume and select your preferred mix ratio below to get an instant, precise measurement of 2-stroke oil required for safe engine operation.
Mix Details
Enter your fuel volume to see the required oil amount
Mixing Results
Required oil volume & instructions
Common 2-Stroke Mix Ratios
A quick-look reference table for the most common 2-stroke fuel-to-oil ratios, showing the exact amount of oil needed per unit of petrol.
| Mix Ratio | Oil per 1 Litre | Oil per 5 Litres | Oil per 1 US Gallon |
|---|---|---|---|
| 50:1 | 20 ml | 100 ml | 2.6 fl oz |
| 40:1 | 25 ml | 125 ml | 3.2 fl oz |
| 32:1 | 31.3 ml | 156 ml | 4.0 fl oz |
| 25:1 | 40 ml | 200 ml | 5.1 fl oz |
Fuel Mix Ratio FAQ
Everything you need to know about mixing 2-stroke fuel and maintaining your small engine equipment.
To calculate a 50 to 1 fuel mix, divide the total volume of petrol by 50. For example, for 5 litres of petrol, divide 5 by 50 to get 0.1 litres (or 100 ml) of 2-stroke oil. Always add the oil to the petrol, not the other way around.
A slightly richer oil mix (e.g., 45:1 instead of 50:1) is generally safer than too little oil. However, significantly too much oil can cause excessive smoke, foul the spark plug, gum up the carburettor, and lead to poor engine performance or carbon buildup.
No. You must use oil specifically formulated for 2-stroke engines. Regular 4-stroke motor oil does not burn cleanly at low temperatures and will cause severe carbon buildup, leading to engine damage.
Mixed 2-stroke fuel begins to degrade after about 30 days. For optimal performance and to avoid carburettor issues, it is best to use the mixed fuel within 30 days, or add a fuel stabiliser if you need to store it for up to 3 months.