The TDS to EC Converter estimates the electrical conductivity of a water sample from its total dissolved solids using the relation EC = TDS ÷ factor. The factor depends on the mix of dissolved salts: it is about 0.5 for sodium-chloride-dominated waters, around 0.64 for many natural waters, and up to 0.7 for other salt profiles. Choosing the factor that matches your sample keeps the estimate as close as possible to a true conductivity reading.
Total dissolved solids (TDS) is the combined mass of all dissolved ions and minerals in water, expressed in parts per million (ppm), which for water is effectively milligrams per liter. Electrical conductivity (EC), measured in microsiemens per centimeter (µS/cm), describes how readily the water carries an electric current. Pure water conducts poorly; every dissolved ion adds charge carriers, so conductivity rises in step with the dissolved content.
The conversion is used wherever conductivity meters meet TDS-based targets. EC meters are inexpensive and instant, but hydroponic nutrient recipes, aquarium-keeping guidelines, and water-treatment specifications are frequently written as TDS values in ppm. Converting in this direction lets you check what conductivity your meter should show for a target TDS — or translate a recipe written in ppm into the EC reading you need to dial in.