Salinity Calculator

This calculator derives salinity from a value of the in situ conductivity (as determined, for example, by a CTD), temperature and pressure.


Enter your values:

conductivity (mmho/cm):   temperature (°C):   pressure (10 kPa):

  S = 

Note: 10 kPa = 1 dbar is close to the pressure increase that corresponds to a depth increase of 1 m.
Entering a pressure value equal to the depth in metres will give an approximate result.

Temperature uses IPTS-68, salinity uses PSS-78; see reference.

Calculation based on Fofonoff, P. and R. C. Millard Jr (1983) Algorithms for computation of fundamental properties of seawater. Unesco Technical Papers in Marine Science 44, 53 pp.

Note: This calculator determines salinity from measurements of in situ conductivity (as obtained, for example, while lowering a CTD). The quantity used in the determination of salinity in bench salinometers is the conductivity ratio Rt(S,t) = C(S,t,0) / (C,35,t,0) where S is salinity, t is temperature and C is conductivity. To determine salinity from this salinity ratio, use the salinity from conductivity ratio calculator.

© 2000 M. Tomczak. Last updated 22 August 2000

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