E6BPilot Computer
Free calculator

Aviation unit converter

Nine conversions pilots use, each with the formula behind it. Type in either box.

Example values — change any of them

Distance

nm
sm
sm = nm × 1.15078
ft
m
m = ft × 0.3048

Speed

kt
mph
mph = kt × 1.15078
mph
km/h
km/h = mph × 1.60934
km/h
m/s
m/s = km/h × 0.277778

Pressure

inHg
mb
mb = inHg × 33.8639
hPa
psi
psi = hPa × 0.0145038

Temperature

°C
°F
°F = °C × 1.8 + 32
K
°C
°C = K − 273.15

Worked examples

  1. 29.92 inHg: mb = 29.92 × 33.8639 = 1013.2079 mb
  2. 100 kt: mph = 100 × 1.15078 = 115.078 mph
  3. 15 °C: °F = 15 × 1.8 + 32 = 59 °F

The units on a flight

Distances and speeds are mostly nautical miles and knots, with statute miles and mph in some older aircraft documents. Altitudes are in feet in most of the world and in metres in a few countries. The altimeter setting is in inches of mercury in North America and hectopascals almost everywhere else.

Millibars and hectopascals are the same unit: 1 mb is 1 hPa.

The factors

Each formula shows its factor rounded to six significant figures. The conversion itself uses the full factor, so a result can differ from the rounded factor in its last digits.

Density altitudePressure altitudeCrosswindCloud baseWeight and balance

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Safety

For training and supplemental situational awareness only. Not for use as the sole basis for flight planning, performance, or operational decisions. It is not an approved flight planning tool, electronic flight bag (EFB), or primary source of aeronautical information. Always use current aircraft documents, an official briefing, and pilot judgment.