Salinity Conversion Calculator
Convert electrical conductivity measurements to practical salinity units (PSU) using the UNESCO practical salinity scale. Essential for oceanography, aquaculture, and water quality monitoring.
Salinity Conversion
intermediateConvert between conductivity and practical salinity units
Formula
PSU from conductivity ratio
How It Works
Salinity is calculated from the conductivity ratio (Rₜ = sample conductivity / standard seawater conductivity at 15°C = 42,900 μS/cm). This uses the UNESCO Practical Salinity Scale (PSS-78) polynomial.
Rₜ = Conductivity / 42,900
S = 0.0120 − 0.2174×Rₜ^0.5 + 25.3283×Rₜ + ...
Frequently Asked Questions
What is typical seawater salinity?
Open ocean salinity is typically 33-37 PSU (average ~35 PSU). Brackish water ranges from 0.5-30 PSU. Freshwater is <0.5 PSU. Hypersaline environments can exceed 50 PSU.
Why does temperature matter for salinity measurement?
Conductivity is temperature-dependent — it increases ~2% per °C. Temperature must be measured simultaneously for accurate salinity calculation. Most modern CTD instruments account for this automatically.