Table 53B turns a hydrometer reading at any temperature into density at 15 °C. Table 54B takes that density at 15 °C and the fuel's temperature and gives the volume correction factor, which turns litres at that temperature into litres at 15 °C. You use 53B first, then 54B.
Two tables, two questions
| Table 53B | Table 54B | |
|---|---|---|
| Question | What is this fuel’s density at 15 °C? | How many litres at 15 °C is this volume? |
| You enter | Hydrometer reading and its temperature | Density at 15 °C and the fuel’s temperature |
| You get | Density at 15 °C, kg/m³ | Volume correction factor (VCF) |
Worked example
A tank holds 12,000 litres of petrol at 32 °C. A sample reads 729.8 kg/m³ at 32 °C on the hydrometer.
- Table 53B: 729.8 at 32 °C gives a density at 15 °C of 745.0 kg/m³.
- Table 54B: density 745, temperature 32 °C gives a VCF of 0.9793.
- Litres at 15 °C: 12,000 × 0.9793 = 11,751 litres.
The 249-litre difference is not lost fuel. It is the same fuel, measured warm. Cool it to 15 °C and it would fill 11,751 litres.
Why both come from one formula
Both tables are built on the same thermal expansion coefficient, chosen by density at 15 °C. Table 54B is that formula applied to volume. Table 53B is the same formula run backwards, with a small extra term for the glass of the hydrometer, which also expands with heat. That is why our VCF calculator and density calculator always agree with each other.
Figures here are for reference. Your oil company’s certified calibration chart, approved instruments and the Marketing Discipline Guidelines always prevail.
Questions
Do petrol pumps need Table 54B?
The daily checks in the MDG use Table 53B. Table 54B matters when you want to compare stock or deliveries at a common temperature, as depots and large customers do.
What about Tables 53A and 54A?
The A tables are for crude oil. Petrol, diesel, kerosene and jet fuel use the B tables.