Gas Oil Mixture Ratio Calculator

US Values
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Gasoline US Gallons
Gas/Oil Mixture Ratio :1
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Oil Required US Ounces
Metric Values
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Petrol Liters
Petrol/Oil Mixture Ratio :1
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Oil Required Milliliters

Fuel & Oil Mixture Chart - Two-Cycle Engines

Two-cycle engines run on a mixture of gasoline and oil. Each engine type is designed to run on a specific gas-to-oil mix ratio. To confirm the correct ratio for your equipment, check your Operator's Manual.

IMPORTANT: Use only oil that is labeled for use in “Two-cycle” or “Two-stroke” engines. Two-cycle oil is available at most major retail stores, automotive supply stores.

NOTE: Synthetic oil is perfectly fine to use, but it must be mixed in the exact ratio specified for the engine. Do not follow any instruction on the oil package that says otherwise.

To mix two-cycle fuel, start by putting the correct amount of oil in the gas can. Then slowly add the correct amount of gasoline. Do not try to mix the gas and oil directly in the gas tank of the equipment.

IMPORTANT: Do not use any fuel that is over 30 days old. Do not mix more fuel than you are likely to use in a month.

What fuel mix do I need?

Always refer to the product engine Operator's Manual for the correct ratio for that engine.

The chart below shows the correct amount of oil per gallon that each mixing ratio requires.
It also shows the amount per Imperial Gallon and per Liter for our *International customers located outside of the United States.

OIL per 1 U.S. GALLON Gasoline
(128 oz.)
(160 oz.)
OIL per 1 LITER Gasoline


4 oz.

5 oz.

31.25 mL


3.2 oz.

4 oz.

25 mL


2.6 oz.

3.2 oz.

20 mL

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What is the Gas to Oil Mixture for My Outboard Motor?

The short answer is 50:1.That is 50 parts gas to 1 part oil.

Most outboard motors run this mix. Some very small outboards tell you 100:1 but I recommend you run 50:1. The logic here is that I would rather replace an occasional spark plug then blow up the motor. The decision is yours but that is my 2 cents.

Some older outboards 50's, 60's and some older recommended mixtures as oil rich as 24:1. Oil has changed alot since those days. I leave it up to you to decide in these cases.

Mixture chart for 50:1 ratio
1 gal gas to 2.6 oz oil
2 gal gas to 5.1 oz oil
3 gal gas to 7.7 oz oil
4 gal gas to 10.2 oz oil
5 gal gas to 12.8 oz oil
6 gal gas to 15.4 oz oil

Most portable out board tanks are 6 gallon tanks. The most common practice is to mix 1 pint (16 oz) to the 6 gallons of fuel that they hold.

The most common moped, or "liquor sickle", out on the market contains a two-stroke cycle engine.

Check your moped's owner's manual for the correct gas to oil ratio. Although moped manufacturers may differ, the most common ratio is 50:1.

(Better yet get rid of the death trap you are riding at 35 mph.)

What Is the Gas to Oil Mixture Ratio for Chain Saws?

The general ratio for most two-stroke chain saw combustion engines is 50:1, though some manufacturers recommend 40:1. The larger number represents the amount of gasoline, while the smaller is the amount of oil needed. If you are treating 1 gallon of clean unleaded gasoline, a 50:1 ration translates to 2.5 ounces of two-cycle oil, while preparing a 40:1 blend calls for 3 ounces of oil.

Use the same type of container designed for gasoline storage, measure correctly and mix the fuel completely before filling your chain saw. It's best to use the premixed gas within a few days and to shake it well anytime it's been sitting for a while to redistribute the oil completely into the gas.

What Is the Gas to Oil Mixture Ratio for A Weed Eater/Trimmer?

The fuel-oil mixture ratio for all Weed Eater products is 40:1. You can obtain this ratio by mixing 3.2 oz. of two cycle air cooled engine oil with one gallon of regular gas. Over a period of time oil will separate from gasoline. To properly insure oil and gas mixture, we recommend thoroughly shaking your oil and gas mixture before refueling your unit.

All Weed Eater two-cycle products require oil to be added to the gas. Unlike engines that have separate gas and oil reservoirs, two-cycle engines run on a gas/oil mixture that keeps the engine lubricated at all times. Never use straight gas in a two-cycle engine as straight gas will ruin the engine within minutes.

What Is the Gas to Oil Mixture Ratio for A Jet Ski?

Is your oil injection tank still in? That tank must remain in the ski. Even going premix, it supplies oil to the rotary chamber....
The premix ratio is 40 or 50:1....but you must make sure you use the right type oil. It must be a non-NMMA, non-TCW-3, low ash oil. Any other oil will blow your motor.

What Is the Gas to Oil Mixture Ratio for A Dirt Bike?

The safest, easiest and best answer is mix it at the ratio recommended by the manufacturer of your dirt bike.

Keep in mind the ratios the manufacturers recommend are for a high performance dirt bike that is designed to race at its full capacity. If you have skills like Ryan Dungey and you ride your bike at full noise most of the time you need the recommended petrol to oil mix to keep the piston and rings properly lubricated. On the other hand, if you are just pottering around and spending most of your bikes time in the low to mid revs range, that extra oil is probably an overkill and not entirely needed.

The problem with veering away from the recommended fuel/oil ratio is the carburetor is set up for the right amount of petrol/oil/air mixture, so if you significantly alter this ratio you will need to change the jets and carby settings to suit.

Two Stroke Fuel Ratio Chart

Mls per liter Oz per gallon
25:1 40 5.12
32:1 31 4.0
40:1 25 3.2
50:1 20 2.56

How to read ratio charts: Ex. 25:1 (pronounced 25 to 1) means for every 25 parts/units of gas you must add 1 part of oil.

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