Gas Oil Ratio Calculator

This gas/oil ratio calculator can be used for determining the amount of oil needed for any gas/oil ratio required by the manufacturer's instructions for two-stroke engines.

How to use this calculator:

1. Input the required gas/oil ratio.
2. Input the quantity of gasoline in US gallons, UK gallons or liters.
3. Click the "Calculate" button to find the quantity of oil required.

Reference

Two-stroke (sometimes called 2-cycle) engines run on a mixture of gasoline and oil. When the substances are mixed, they both lubricate the engine and create combustion. All two-stroke engines are designed for a particular ratio of gas/oil mixture. To check you have the right ratio for the engine you're using, check in the operating manual. If you put gasoline in a two-stroke engine without oil in the engine will fail.

This calculator allows you to work out the exact ratio of oil and gas needed for any two-stroke engines.

How to mix oil and gas

Step 1: Begin by checking you are using the right measurement, as different countries use different units, i.e. liters, UK gallons, or US gallons. Find the correct oil/gas ratio for your particular engine. A number of fuel ratios may be used, e.g., 24:1, 32:1, 40:1, 50:1, etc. The ratio tells you the quantity of fresh standard unleaded gasoline (10% ethanol or lower) is needed for a specific quantity of oil.

Step 2: Mixing should take place in a fuel can, not inside the tank.

Step 3: Once you have mixed the fuel, pour it into the tank and you're good to go. Use the same ratio and operations every time your engine needs more fuel.

Formulas & Examples

The Gas Oil Ratio Calculator employs the basic formulas below:

((128 * US Gallons) / Ratio) = US Ounces of Oil

((160 * UK Gallons) / Ratio) = UK Ounces of Oil

((1000 * Liters) / Ratio) = Milliliters of Oil

Example 1: You've got 1 US gallon of gas, and your engine needs a gas/oil mix of 40:1. There are 128 oz in 1 US Gallon. You'll have to add ((128 × 1) / 40) = 3.2 US ounces of oil.

Example 2: You've got 5 UK gallons of gas, and your engine needs a gas/oil mix of 32:1. You'll have to add ((160 × 5) / 32) = 25 UK ounces of oil.

You may also be interested in our Alternative Fuels Conversion Calculator