# Density variation calculator

> A free calculator for the MDG 2024 tanker density check: hydrometer reading to density at 15 °C by Table 53B, compared with the invoice density, within ±3.0 kg/m³ or not.

Canonical: https://dipdensity.watsinfo.com/tools/density-variation-calculator/
Last updated: 2026-11-02

**Short answer:** Type the density at 15 °C printed on the invoice, then your hydrometer reading and its temperature. The calculator works out your density at 15 °C by Table 53B and the difference. The Marketing Discipline Guidelines allow ±3.0 kg/m³.

The calculator runs in the browser at https://dipdensity.watsinfo.com/tools/density-variation-calculator/.

## The rule

Clause 1.2 (iv) of the Marketing Discipline Guidelines 2024 reads: the dealer is "to check that the Density of product @ 15°C using ASTM Tables (53B) is within +/- 3.0 Kg/M3 as compared with the Invoice density for ascertaining quality of product."

## Why density gives adulteration away

Petrol and diesel each sit in a narrow density band. Kerosene, solvents or naphtha mixed in move the density. A drop or rise of more than 3 kg/m³ against the depot's own figure is the first sign that what is in the tanker is not what was loaded.

## Write it down

Record each compartment in the density register (Annexure 1 of the MDG): the date, the tank truck receipt density by compartment, the invoice density, and, after decanting and dispensing 50 litres, the density of the mixed product in your tank.

## Questions

### What if the difference is more than 3 kg/m³?

Do not decant. Take a fresh sample and read again. If it is still outside, contact the supply location or your area officer for instructions, as clause 1.2 (ix) of the MDG says.

### Do I check every compartment?

Yes. The MDG asks for about 20 litres to be drained from the manifold of each compartment into a clear glass jar, and each compartment to be checked and recorded on its own.

## Sources

- [BPCL, Marketing Discipline Guidelines 2024](https://www.bharatpetroleum.in/images/files/MDG-2024-Effective-24-10-2024.pdf)