Total Dissolved Solids from Conductivity

\[TDS=k\,EC\]

Variables

TDStotal dissolved solids (mg/L)

ECelectrical conductivity (µS/cm)

kconversion factor (-)

Description

What is this formula?

This formula estimates Total Dissolved Solids (TDS) from electrical conductivity measurements using an empirical conversion factor.

When to use it

Use it when rapid estimation of dissolved solids is needed and direct laboratory TDS measurements are unavailable.

Example

Data:

EC = 800 µS/cm

k = 0.65

Formula:

TDS = k · EC

Substitution:

TDS = 0.65 × 800

Result:

TDS = 520 mg/L

Applications

Water treatment, groundwater monitoring, irrigation water assessment, aquaculture, drinking water evaluation, environmental monitoring, and industrial water management.

Note

This is an empirical approximation. The conversion factor k typically ranges from about 0.5 to 0.9 depending on water chemistry and dissolved ion composition. Different industries and regulatory agencies may recommend different values of k.