It is pretty easy to calculate. When it is necessary to calculate motor gasoline, diesel fuel, and liquefied gas not in volume but weight units, their actual density (specific gravity) should be taken as the primary calculation unit. You need to multiply the number of litres available by the actual density to do this. Then the result is divided by 1000, and the desired number is obtained.
The only thing that can negatively affect fuel conversion from litres to tons is the temperature. The hotter, the higher the specific gravity of the fuel. Therefore, to facilitate and perform such calculations without errors, the Ministry of Industry and Energy of the Russian Federation decided to average the density value of gasoline. For example, for fuel A-76 (AI-80), the average specific gravity is 0.715 grams per cubic centimetre. For AI-92 gasoline, the average actual density is set at 0.735 grams per cubic centimetre, and for AI-95, it is 0.750 grams. As for AI-98 fuel grade, the average specific gravity is 0.765 grams per cubic centimetre.
If it is necessary to calculate the conversion from litres to tons of diesel fuel (this is often necessary for the retail trade), you should use the following formula: M = V x 0.769 / 1000. Here M is the volume of diesel fuel in tons, V is the volume of diesel fuel in litres, and 0.769 is the density indicator of diesel fuel based on kilograms per litre.
You can use the average value used in Rostekhnadzor to calculate the conversion from fuel to tons. They have adopted their standards for calculating fuel density. So, for liquid gas, the average value is 0.6 tons per cubic meter, gasoline – 0.75 tons per cubic meter, and diesel, 0.84 t/m3.