TDS Level Calculator
Choose a method, enter the available water data, and calculate estimated total dissolved solids.
Example Data Table
| Sample | EC | Factor | Estimated TDS | Typical Interpretation |
|---|---|---|---|---|
| Reverse osmosis water | 35 µS/cm | 0.64 | 22.40 ppm | Very low dissolved solids |
| Filtered tap water | 420 µS/cm | 0.64 | 268.80 ppm | Moderate level |
| Hard source water | 950 µS/cm | 0.64 | 608.00 ppm | High mineral content |
| Brackish sample | 2100 µS/cm | 0.64 | 1344.00 ppm | Very high level |
Formula Used
How To Use This Calculator
TDS Level Guide
Understanding TDS Readings
Total dissolved solids describe the minerals, salts, metals, and other dissolved matter in water. A meter does not usually count every particle directly. It reads electrical conductivity, then estimates concentration with a conversion factor. That is why two meters can show different values for the same sample.
Why TDS Matters
TDS is useful for drinking water checks, aquarium care, hydroponics, boilers, car washing, pools, and laboratory preparation. Very low readings can mean the water has few dissolved minerals. High readings can point to heavy mineral load, brine, fertilizer carryover, or treatment problems. Taste can also change as the number rises. Still, TDS is not a full safety test. Clear water with a modest reading can still contain harmful pollutants.
Using the Calculator Results
This calculator supports four common methods. Conductivity mode converts EC into estimated ppm. Mass and volume mode finds concentration when you know dissolved material weight and water volume. Dilution mode estimates how much pure water is needed to reduce a sample. Mixing mode predicts the final TDS after combining two water sources. These options help you compare choices before treating or blending water.
Interpreting Water Quality
A balanced reading depends on use. Drinking water often feels pleasant in the middle range. Hydroponic plants may need controlled nutrient strength. Aquariums may require species specific mineral levels. Steam systems often need lower solids to reduce scaling. Reverse osmosis systems should show a large drop from feed water to product water. Always compare results with your equipment manual, local guidance, and professional testing when health or compliance matters.
Better Testing Habits
Rinse the meter probe before each sample. Use a clean cup. Stir gently and wait for the reading to stabilize. Record temperature, source, date, and treatment stage. Calibrate the meter when results drift. Test raw water and treated water separately. A single reading is only a snapshot. Repeated records reveal trends, filter exhaustion, and blending errors. Good notes make every TDS reading more useful.
When a value looks unusual, repeat the test. Check battery strength and probe cleanliness. Compare against a known solution. Small habits reduce false alarms and improve decisions for every user at home.
FAQs
What does TDS mean?
TDS means total dissolved solids. It estimates dissolved minerals, salts, metals, and similar material in water. It is usually shown as ppm or mg/L.
Is TDS the same as water safety?
No. TDS shows dissolved solids, not bacteria, pesticides, lead, or every harmful contaminant. Use lab testing when health or legal safety matters.
What conversion factor should I use?
Many meters use factors around 0.5 to 0.7. Use the value from your meter manual when available. The default here is 0.64.
Why do two meters show different TDS values?
Meters may use different conversion factors, calibration standards, temperature compensation, and probe quality. Clean and calibrate probes for better repeatability.
Can this calculator help with dilution?
Yes. Dilution mode estimates how much low TDS or pure water you need to add to reach a lower target level.
Can I use this for hydroponics?
Yes, it can estimate nutrient strength from EC. Always compare the result with crop stage, nutrient brand guidance, and your meter scale.
Does temperature affect readings?
Yes. Conductivity changes with temperature. Many meters compensate automatically, but readings are usually most reliable after temperature stabilizes.
What is a good TDS level?
A good level depends on use. Drinking water, aquariums, boilers, plants, and lab work all have different target ranges and tolerances.