basic

Seawater Freezing Point Depression Calculator

ΔT_f for an aqueous NaCl solution from salinity.

Compute the freezing point of seawater (or any aqueous NaCl solution) from its salinity using the colligative-property formula ΔT_f = i · Kf · m, with i ≈ 1.85 for NaCl, Kf = 1.853 °C·kg/mol, and converting salinity to molality.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

g/kg

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

ΔT_f = i · Kf · m; m ≈ salinity_g_per_kg / 58.44.

In depth

Compute the freezing point of seawater (or any aqueous NaCl solution) from its salinity using the colligative-property formula ΔT_f = i · Kf · m, with i ≈ 1.85 for NaCl, Kf = 1.853 °C·kg/mol, and converting salinity to molality.