How Much 2-Stroke Oil for 1 Liter of Gas?
At 50:1, add 20 mL (0.7 fl oz) of 2-stroke oil.
At 40:1, add 25 mL (0.8 fl oz).
At 32:1, add 31 mL (1.1 fl oz).
Not sure which ratio? Use the one in your owner's manual or on the fuel cap. Most modern handheld equipment is 50:1. Other amounts: open the calculator.
One litre is the size of most mixing bottles and small fuel bottles used for chainsaws and trimmers, especially in metric countries. At this size, a few millilitres of error changes the ratio noticeably, so use a syringe or a marked mixing bottle.
Oil for 1 Liter at Every Ratio
| Ratio | Oil (fl oz) | Oil (mL) | Easy measure | Typically used for |
|---|---|---|---|---|
| 50:1 | 0.7 fl oz | 20 mL | about 4 teaspoons | Modern chainsaws, trimmers, blowers; most modern outboards |
| 40:1 | 0.8 fl oz | 25 mL | about 5 teaspoons | Older equipment, some trimmers and outboards, many dirt bikes |
| 32:1 | 1.1 fl oz | 31 mL | about 6.5 teaspoons | Dirt bikes and motocross, high-load engines |
| 30:1 | 1.1 fl oz | 33 mL | about 7 teaspoons | Vintage outboards |
| 25:1 | 1.4 fl oz | 40 mL | about 8 teaspoons | Older equipment, break-in when specified |
| 20:1 | 1.7 fl oz | 50 mL | about 10 teaspoons | Vintage engines, some racing |
| 16:1 | 2.1 fl oz | 63 mL | about 4 tablespoons | Antique engines and outboards |
1 liter is 0.26 US gallons. The mL amounts above are exact for any metric ratio: divide the fuel in mL by the ratio (1000 ÷ 50 = 20 mL).
How Precise Do You Need to Be?
Staying within about 10% of the target amount keeps you close to the intended ratio. For 1 liter at 50:1 that means 18–22 mL of oil, and at 40:1, 23–28 mL.
At this batch size, an extra 10 mL of oil turns a 50:1 mix into about 33.3:1, and 10 mL too little makes it about 100:1. Running slightly rich (more oil) is safer for the engine than running lean.
Mixed 1 Liter at the Wrong Ratio?
You don't need to throw it out. To correct a full 1-liter batch:
| Situation | Fix |
|---|---|
| Mixed 40:1, need 50:1 | Add 0.25 liters of fresh gas (1.25 liters total) |
| Mixed 50:1, need 40:1 | Add 5 mL more oil |
| Mixed 50:1, need 32:1 | Add 11 mL more oil |
| Mixed 32:1, need 50:1 | Add 0.56 liters of fresh gas (1.56 liters total) |
Adding gas makes the batch bigger, so only lean out a mix if you will use the extra fuel within about a month.
How to Mix 1 Liter
- Measure the oil, for example 20 mL (0.7 fl oz) for 50:1. A ratio measuring cup reads directly in ounces and mL.
- A 1-litre mixing bottle with printed ratio lines is the easiest way to get this right.
- Cap it tightly and shake for about 30 seconds. A fuel can with a sealing cap prevents spills while you shake.
- Write the ratio and date on the can. Shake again before each refill if the can has been sitting.
1 Liter: Common Questions
How much oil for 1 liter of gas at 50:1?
1 liter at 50:1 needs 20 mL (0.7 fl oz) of 2-stroke oil.
How much oil for 1 liter of gas at 40:1?
1 liter at 40:1 needs 25 mL (0.8 fl oz) of 2-stroke oil.
How much oil for 1 liter of gas at 32:1?
1 liter at 32:1 needs 31 mL (1.1 fl oz) of 2-stroke oil.
I mixed 1 liter at 40:1 but my engine needs 50:1. What do I do?
Add 0.25 liters of fresh gas (1.25 liters total). That brings the batch back to 50:1 without wasting it.
How long does 1 liter of mixed fuel last?
Mixed 2-stroke fuel without stabilizer is best used within about 30 days. A fuel stabilizer extends that; follow the storage time on the stabilizer's label.
Other Fuel Amounts
Need a ratio guide instead? See 50:1, 40:1, 32:1 or all ratios.