Fuel oil specific weight: density and weight of 1 m³

Fuel oil is a dark viscous petroleum product obtained as a residue from crude oil refining or from secondary processing of petroleum fractions. It is used as fuel for boiler plants, industrial furnaces, power units and marine systems.

In common search queries this value may be called the specific weight of fuel oil, although tables usually give density in g/cm³ or kg/m³. For practical calculations, density is the key value because it shows how much 1 m³ of fuel oil weighs at a given temperature.

Fuel oil density and weight table

Fuel oil density depends on grade, composition, water content and temperature. When heated, density decreases; when cooled, it increases. For approximate calculations, a range of 0.89-1.01 g/cm³ can be used.

For accurate calculations, use the quality certificate for the specific batch. Different heating and marine fuel oils can vary noticeably in density, and for some grades standards may require density to be determined even if it is not limited by a fixed value.

How to calculate fuel oil mass

Fuel oil mass is calculated by the formula:

mass = volume × density

If fuel oil density is taken as 950 kg/m³, then 5 m³ will weigh:

5 × 950 = 4750 kg

So 5 m³ of this fuel oil will have a mass of about 4.75 t.

Specific weight and density of fuel oil

Technically, specific weight is the weight per unit volume and is calculated from density: γ = ρ × g, where ρ is density and g is gravitational acceleration, about 9.81 m/s². In SI units, specific weight is measured in N/m³.

In practical construction and fuel calculations, “fuel oil specific weight” often means density or mass of 1 m³. For purchasing, storage and transport, values in kg/m³ or t/m³ are normally used.

What affects fuel oil density

Fuel oil density and weight depend on:

• fuel grade and composition;
• measurement temperature;
• water and mechanical impurities;
• share of heavy residual fractions;
• storage and heating conditions.

For equipment operation, density is not the only important parameter. Viscosity, flash point, sulfur, water and ash content also matter. Unsuitable fuel can worsen atomization, combustion and operation of boilers, burners or marine systems.