Sea-Level Pressure Correction Calculator

Convert station pressure to sea-level pressure from elevation and temperature using the standard atmospheric reduction formula.

Input

Enter the station pressure, elevation, and temperature to compute the sea-level pressure and the correction amount.

Station pressure

hPa

Pressure measured at the observation site (hPa)

Elevation

Height of the observation site above sea level (m)

Temperature

degrees C

Air temperature at the observation site (degrees C)

Sea-level pressure

1,020.970202hPa

Reduced from a station pressure of 1,003 hPa

Correction

17.970202 hPa

Temperature

15 degrees C

Calculated with the reduction formula using the standard lapse rate of 0.0065 degrees C per meter.

Sea-level pressure P0 is found from station pressure P, elevation h (m), and temperature T (degrees C) by P0 = P × ( 1 − L·h /（T + L·h + 273.15 ） )^(−5.257).
L is the standard atmospheric lapse rate, taken as 0.0065 degrees C per meter. The value 273.15 is the absolute temperature (K) of 0 degrees C.
The exponent 5.257 is an approximation derived for dry air from gravity g = 9.80665 m/s squared, gas constant R = 287.05 J per kg per K, and lapse rate L = 0.0065 degrees C per meter.
The correction amount is the sea-level pressure minus the station pressure, and it grows with elevation.
This is an estimate based on the standard formula and may differ in detail from the official reduction methods used by weather agencies.

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