Bunker Density vs Temperature

Correct fuel density from the delivery temperature to 15 °C using the ISO 91-1 linear formula. Converts a litre-based bunker volume into the contractual mass.

VoyageBunkersISO 91-1

Bunker figures

Density at 15 °Ckg/m³From the BDN certificate of quality.Temperature at delivery°CVolume delivered (observed)m³

Density at observed T: 967.60kg/m³

Mass: 483.800t

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\rho_T = \rho_{15} - \alpha (T - 15)

Symbol	Meaning	Unit
$\rho_T$	Density at delivery temperature	kg / m³
$\rho_{15}$	Certified density at 15 °C	kg / m³
$T$	Observed bunker temperature	°C
$\alpha$	Volumetric expansion coefficient - 0.64 (residual) / 0.70 (distillate)	kg / m³ / °C
$V_\text{obs}$	Observed bunker volume	m³
$m$	Delivered mass	t
$10^{-3}$	Kilograms → tonnes

Source: ISO 91-1 - *Petroleum measurement tables*; ISO 8217 - *Marine fuels specification*

In short

Correct marine fuel density from observed temperature to 15 °C per ISO 91-1 and convert bunker volume to mass.

Learn the theory Bunker Quality and ISO 8217 Marine Fuel Standards