Fuel Density Correction Calculator

Work out fuel density correction instantly with clear inputs, formula shown and shareable results.

About Fuel Density Correction Calculator

Petroleum expands with temperature, so density measured hot must be corrected to a reference temperature — 15 C internationally or 60 F in North America. The correction is density x (1 + alpha x temperature difference), with alpha around 0.0007 per degree for middle distillates and 0.0009 for gasoline.

Formulas

Density correction

Density at reference = observed density x (1 + alpha x (T_observed - T_reference))

API gravity

API = 141.5 / SG at 60 F - 131.5

Worked example

With the default values below, Fuel Density Correction Calculator returns Density At Reference Temperature of 855.343. Change any input above and every figure here is recalculated in your browser.

Inputs used

Observed Densityminimum 0.01 kg/m3: 845 kg/m3
Observed Temperatureminimum -50 degrees C: 32 degrees C
Reference Temperatureminimum -50 degrees C: 15 degrees C
Expansion Coefficientminimum 0 per degree C: 0.00072 per degree C

Results

Density At Reference Temperature: 855.343
Volume Correction Factor: 0.987908
Temperature Difference: 17.00
API Gravity At Reference: 33.768

Step by step

1Values used
2Density correction
3API gravity
4Density At Reference Temperature= 855.343
5Volume Correction Factor= 0.987908
6Temperature Difference= 17.00
7API Gravity At Reference= 33.768

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Custody transfer measurement must use the volume correction tables prescribed by the applicable measurement standard and contract.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Custody transfer measurement must use the volume correction tables prescribed by the applicable measurement standard and contract.

Frequently Asked Questions

Why does custody transfer require correction?

A tanker loaded at 40 C and discharged at 15 C contains the same mass but different volume. Correcting to a standard temperature is the only way volumes can be reconciled and taxed consistently.

Which standard should be used?

The API MPMS Chapter 11 tables, or the ASTM D1250 volume correction factor tables. Simple linear expansion is adequate for estimation but not for custody transfer.