Aviation Unit Converter

The ones that catch people

Fuel weight is not one number. Avgas is about 6.0 lb per US gallon, Jet A about 6.8. Both vary with temperature — colder fuel is denser, so a gallon weighs more — which matters for weight and balance at the margins.

Imperial and US gallons differ by about 20%. An imperial gallon is 4.55 liters against the US 3.79. Refueling in a country that uses one while planning in the other is a genuine and recurring source of fuel exhaustion.

Altimeter settings come in two flavors. Inches of mercury in North America, hectopascals almost everywhere else. 29.92 inHg is 1013.25 hPa, and one inch is about 34 hPa.

Nautical and statute miles are not interchangeable. Visibility in a US METAR is statute; distances on charts and in flight planning are nautical. A nautical mile is 1.15 statute miles, which is enough to matter when the visibility minimum is 3.