Calculadora de TDS
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
TDS = condutividade × fator (padrão 0,64)
About this calculator
The TDS Calculator converts the electrical conductivity of a solution (measured in µS/cm) into total dissolved solids (TDS, in ppm or mg/L). The conversion uses a standard empirical factor of 0.64, widely adopted in water analysis to estimate the concentration of dissolved salts. This correlation is based on the linear relationship between conductivity and the amount of ions present in the solution.
Operation is simple: enter the conductivity value and adjust the conversion factor if needed (default is 0.64). The calculator multiplies conductivity by the factor, providing an estimated TDS. Note that the factor may vary depending on the ionic composition of the water; for natural waters, 0.64 is a good approximation, but for specific solutions (e.g., industrial effluents) a different factor may be required.
Use this calculator in situations such as monitoring drinking water quality, aquariums, irrigation systems, or industrial processes that require control of dissolved salts. It is useful for a quick estimate without complex equipment. However, remember it is an empirical correlation: for accurate results, gravimetric methods or calibrated instruments are recommended.
Caution: the 0.64 factor is an average and may not be suitable for waters with high concentrations of specific ions (e.g., chlorides or sulfates). Also, conductivity is temperature-dependent; ideally, measurements should be made at 25°C or with temperature compensation. Always verify the factor's validity range for your specific application.
Frequently asked questions
What does TDS mean?
TDS stands for Total Dissolved Solids, which is the amount of dissolved substances in water, such as mineral salts, metals, and other ionic compounds.
Why is the default factor 0.64?
The 0.64 factor is an average empirical correlation for natural waters, based on the relationship between conductivity and ion concentration. It can range from 0.5 to 0.7 depending on water composition.
Can I use this calculator for seawater?
It is not recommended, as seawater has a different ionic composition, with a typical conversion factor around 0.5. The calculator uses 0.64, which may overestimate TDS.
Does temperature affect the result?
Yes, conductivity varies with temperature. For greater accuracy, measure conductivity at 25°C or use a meter with automatic temperature compensation.
What is the difference between TDS and conductivity?
Conductivity measures the water's ability to conduct electric current, related to the amount of ions. TDS estimates the total mass of those dissolved ions. The conversion depends on the empirical factor.