Calculator Inputs
3 columns large • 2 columns medium • 1 column smallExample Data Table
Typical reference values vary by formulation, additive package, and test standard. Use them for quick comparisons, not for custody transfer.
| Fuel | Typical Density at 15 °C (kg/m³) | Approx. Specific Gravity | Typical β (1/°C) | Common Use |
|---|---|---|---|---|
| Gasoline | 720–780 | 0.72–0.78 | 0.00095 | Spark-ignition engines |
| Diesel | 820–860 | 0.82–0.86 | 0.00083 | Compression-ignition engines |
| Jet A-1 | 775–840 | 0.776–0.841 | 0.00099 | Aviation turbine fuel |
| Kerosene | 780–820 | 0.78–0.82 | 0.00096 | Heating and lighting |
| Ethanol | 785–790 | 0.786–0.791 | 0.00110 | Blending and industrial use |
Formula Used
Density = Mass ÷ Volume
Mass = Density × Volume
Volume = Mass ÷ Density
SG = 141.5 ÷ (API + 131.5)
ρref = SG × 999.016
ρref = ρmeasured × [1 + β × (Tmeasured − Tref)]
Here, β is the volumetric thermal expansion coefficient. The correction is a practical engineering approximation for small temperature ranges.
How to Use This Calculator
- Choose the calculation mode that matches your known values.
- Select a fuel profile, or choose Custom to enter your own β value.
- Enter mass, volume, density, API gravity, or specific gravity as needed.
- Set the measured temperature and the target reference temperature.
- Press Calculate Fuel Density to show results above the form.
- Review the density table, graph, and converted values.
- Use the CSV or PDF buttons to export the calculated summary.
FAQs
1) What is fuel density?
Fuel density is mass per unit volume. It helps estimate stored energy, shipment weight, combustion behavior, and volumetric efficiency in tanks, engines, and measurement systems.
2) Why does temperature matter?
Most fuels expand when temperature rises. Volume increases while mass stays constant, so measured density usually falls. That is why reference-temperature corrections are important.
3) What is API gravity?
API gravity is a petroleum industry scale related to specific gravity. Higher API values usually indicate lighter fuels, while lower values indicate heavier oils.
4) Is specific gravity the same as density?
Not exactly. Specific gravity is a ratio with no unit. Density has units such as kg/m³, g/cm³, or lb/ft³. They are directly related.
5) Can I use this for gasoline, diesel, and jet fuel?
Yes. The built-in profiles provide typical thermal expansion coefficients for several common fuels. For lab-grade work, enter a custom coefficient from your own test data.
6) How accurate is the temperature correction?
It is a practical linear approximation. It works well for moderate temperature ranges. For regulatory or custody-transfer work, follow the required standard tables.
7) Which density unit should I choose?
Choose the unit used in your source data or reporting format. The calculator converts between common engineering and laboratory density units automatically.
8) When should I use custom β?
Use a custom expansion coefficient when you know the actual value for a specific blend, tested batch, or compliance procedure. That improves correction quality.