Compute seawater viscosity using temperature, salinity, pressure, depth. Review density, kinematic viscosity, and plotted behavior. Use exports, examples, formulas, and steps with confidence today.
The example below uses salinity of 35 g/kg across several temperatures.
| Temperature C | Salinity g/kg | Dynamic cP | Dynamic Pa.s | Density kg/m³ | Kinematic cSt |
|---|---|---|---|---|---|
| 5 | 35 | 1.619304 | 0.001619304 | 1027.675 | 1.575696 |
| 15 | 35 | 1.219867 | 0.001219867 | 1025.973 | 1.188986 |
| 25 | 35 | 0.958828 | 0.000958828 | 1023.343 | 0.936957 |
| 35 | 35 | 0.777874 | 0.000777874 | 1019.934 | 0.762671 |
| 45 | 35 | 0.646798 | 0.000646798 | 1015.865 | 0.636697 |
The calculator estimates pure water viscosity first. It then applies a salinity correction to obtain seawater dynamic viscosity.
Pure water viscosity
μw = 4.2844 × 10-5 + 1 / (0.157(T + 64.993)2 − 91.296)
Salinity terms
A = 1.541 + 1.998 × 10-2T − 9.52 × 10-5T2
B = 7.974 − 7.561 × 10-2T + 4.724 × 10-4T2
Seawater dynamic viscosity
μsw = μw(1 + AS + BS2)
Kinematic viscosity
ν = μ / ρ
T is in Celsius. S is salinity in kg/kg inside the viscosity equation. Depth is used only to estimate hydrostatic pressure for reporting.
Seawater viscosity affects pumping, mixing, heat transfer, transport calculations, hydraulic sizing, and marine process analysis. A warmer sample usually flows more easily, while higher salinity usually increases resistance to motion. That is why temperature and salinity are the key controls in this page.
This calculator reports both dynamic viscosity and kinematic viscosity. Dynamic viscosity is helpful when you are working directly with shear behavior, fluid models, or engineering property tables. Kinematic viscosity is useful when density matters, especially in diffusion style comparisons, flow estimates, and Reynolds number style work.
The page also estimates density and hydrostatic pressure so the result feels more complete for practical chemistry or marine calculations. Depth is kept as an informational pressure estimate in this implementation. The main viscosity result still comes from the temperature and salinity relationship used above.
The example table helps you compare several common temperatures at standard seawater salinity. The graph helps you see how dynamic viscosity changes across a temperature sweep at the salinity you entered. This makes trend checking easier before you move into design, reporting, or experiment planning.
It estimates seawater dynamic viscosity, kinematic viscosity, density, dissolved salt loading, and hydrostatic pressure values based on your inputs.
Temperature and salinity control the viscosity result in this implementation. Depth is only used to estimate pressure for reporting.
Dynamic viscosity describes resistance to shear. Kinematic viscosity divides that value by density, which is useful for many flow comparisons.
They are treated as numerically similar for practical calculator use on this page. If your lab uses a stricter convention, enter the matching value carefully.
Yes. The calculator converts Fahrenheit and Kelvin to Celsius before applying the viscosity equation.
The implemented viscosity correlation is most suitable within its recommended temperature and salinity range. The page warns you when you move beyond that range.
As temperature rises, liquid molecules move more freely, so internal resistance to flow usually falls.
Yes. You can download the result as CSV, download a simple PDF summary, or print the page.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.