Aviation unit converter
Fuel from litres or gallons into kilograms and pounds – with the right density for AvGas, UL91, MOGAS or Jet A-1 – and all units you meet between POH, AIP and weather report.
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Fuel: volume and mass
Tanks are measured in litres or gallons, weight and balance in kilograms or pounds. The link is the fuel density: AvGas 100LL and UL91 weigh about 0.72 kg per litre (6.0 lb per US gallon), MOGAS 0.72–0.775 kg/l (typically 0.745), Jet A-1 0.775–0.840 kg/l (typically 0.80, 6.7 lb/US gal) – the range comes from the fuel specifications.
Example: 150 l of AvGas = 108 kg = 238 lb = 39.6 US gal. The same 150 l of Jet A-1 for a diesel engine weigh 120 kg. Density also changes with temperature, by about 1 % per 10 °C – if you know the density on the fuel receipt, enter it.
Units in aviation
Altitudes and flight levels are in feet, visibility in metres or kilometres (statute miles in North America), distances in nautical miles (1 NM = 1.852 km), speeds in knots (1 kt = 1.852 km/h), vertical speeds in feet per minute (100 fpm ≈ 0.51 m/s). Pressure is hPa in Europe and inches of mercury in North America (1013.25 hPa = 29.92 inHg).
One US gallon is 3.785 l, one imperial gallon 4.546 l. Older European aircraft and many POHs from the US use US gallons; some British handbooks imperial gallons.
Typical fuel densities at 15 °C
| Fuel | kg/l | lb/US gal | Source / range |
|---|---|---|---|
| AvGas 100LL | 0.72 | 6.0 | typical value used in POHs |
| UL 91 | 0.72 | 6.0 | typical |
| MOGAS (EN 228) | 0.745 | 6.2 | 0.720–0.775 kg/l (EN 228) |
| Jet A-1 | 0.80 | 6.7 | 0.775–0.840 kg/l (DEF STAN 91-091, ASTM D1655) |
| Diesel (EN 590) | 0.835 | 7.0 | 0.820–0.845 kg/l (EN 590) |
Frequently asked questions
How much does a litre of AvGas weigh?
About 0.72 kg at 15 °C, i.e. 6.0 lb per US gallon. 100 l of AvGas weigh 72 kg.
How much does Jet A-1 weigh?
Between 0.775 and 0.840 kg per litre according to the specification, typically about 0.80 kg/l or 6.7 lb per US gallon. Diesel aircraft engines (Austro, Continental CD) run on Jet A-1, so their fuel is about 10 % heavier per litre than AvGas.
How many litres are in a US gallon?
3.785 litres. An imperial gallon is 4.546 litres.
How do I convert hPa to inHg?
Divide by 33.864: 1013.25 hPa = 29.92 inHg. In the other direction multiply by 33.864.
How many km/h is one knot?
One knot is one nautical mile per hour = 1.852 km/h = 1.151 mph = 0.514 m/s.
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