TDS to PPM Calculator
Convert water TDS (mg/L) to PPM or estimate PPM from EC reading. Ideal for measuring drinking water and hydroponics nutrient strength.
Formula Used
PPM ≈ EC × Scale
TDS (mg/L) = PPM in most practical water testing cases.
TDS to PPM Calculator
Perfect for both drinking water testing and hydroponics growers.
TDS to PPM Calculator
The TDS to PPM Calculator helps convert Total Dissolved Solids (TDS) between mg/L and PPM and also estimates nutrient levels using EC meter readings. This tool is used in water purification, aquarium management, and hydroponics to ensure safe and balanced water quality. You can enter TDS (mg/L), PPM, or EC (mS/cm) to estimate water purity or nutrient strength instantly.
What Is TDS?
TDS stands for Total Dissolved Solids. It represents the total amount of minerals, salts, metals, and ions dissolved in water. It includes:
Calcium and magnesium hardness
Sodium, potassium, chloride
Carbonates and sulfates
Trace metals like iron
Organic matter
TDS affects:
Taste and purity of drinking water
Plant nutrient absorption
Aquarium ecosystem health
Corrosion and scaling in water pipes
TDS is measured in mg/L, which is equal to PPM for dissolved solids.
What Is PPM in Water Quality?
PPM (Parts Per Million) measures how many parts of dissolved substance are present per one million parts of water. When measuring TDS, both PPM and mg/L represent the same concentration:
1 mg/L ≈ 1 PPM (for dissolved solids)
If TDS increases too high, water becomes unsuitable for drinking or harmful to plant roots.
EC to PPM Conversion Explained
Many digital meters measure EC (Electrical Conductivity) instead of PPM. EC shows how well the water conducts electricity based on dissolved ions.
To convert:
PPM ≈ EC × scale
Two scale standards exist:
• 500 scale (USA) — Sodium chloride standard
• 700 scale (Australia/EU) — Potassium chloride standard
Example:
EC = 1.0 mS/cm
Scale = 500
PPM = 500 PPM
Using the wrong scale causes incorrect results, so this tool lets you choose.
Safe TDS Levels for Drinking Water
| TDS (PPM) | Water Quality |
|---|---|
| < 50 | Very low minerals but safe |
| 50–150 | Excellent drinking water |
| 150–300 | Good, acceptable taste |
| 300–600 | Fair quality, common tap water |
| 600–900 | Poor, may cause hardness issues |
| 900–1200 | Bad, possible contamination |
| > 1200 | Unsafe for drinking |
Water filters such as RO systems and UV treatment reduce TDS to safe levels.
Ideal PPM in Hydroponics
Different crops need different PPM for proper growth:
| Plant Type | Recommended PPM |
|---|---|
| Leafy greens | 300–600 PPM |
| Herbs | 200–500 PPM |
| Tomatoes/Peppers | 900–1500 PPM |
| Cannabis (Veg) | 800–1200 PPM |
| Cannabis (Flower) | 1000–1600 PPM |
High TDS risks nutrient lockout and salt burn. Low TDS causes deficiencies. This calculator quickly shows where your water stands.
How the Calculator Works
You enter any one of the following:
TDS (mg/L)
PPM
EC (mS/cm) with selected scale
The calculator detects what you entered and delivers:
Final TDS/PPM value
Formula used
Interpretation message
This ensures the right measurement is always clear.
Example: Drinking Water
Input:
TDS = 180 mg/L
Scale selection not needed
Result:
≈ 180 PPM
Quality: Good
Example: Hydroponics EC Reading
EC = 1.6 mS/cm
Scale = 700
PPM = 1120 PPM
Nutrient strength high enough for fruiting crops
Why TDS and PPM Matter
TDS determines water taste, safety, and suitability for drinking
PPM tells plant growers how much nutrition is present
Aquarists track fish comfort and health
Labs monitor purity for chemistry and food production
The cleaner and balanced the water, the better biological systems function.
FAQ — TDS to PPM Calculator
Is TDS the same as PPM?
Yes. In water testing:
1 mg/L ≈ 1 PPM
Why do some readings differ between meters?
Meters use different conversion scales (500 or 700). Always match the correct scale.
How do I reduce high TDS?
Use:
Reverse Osmosis (RO)
Activated carbon filtration
Ion exchange systems
What is a healthy TDS level in drinking water?
50–250 PPM is ideal with good taste and mineral balance.
Can EC measure water purity?
Yes. EC estimates dissolved ions. This tool converts EC into PPM for easier interpretation.
Summary
The TDS to PPM Calculator is the fastest way to understand water quality and nutrient concentration. It supports TDS, PPM, and EC meters, making it useful for drinking water, aquariums, hydroponics, and industrial water treatment.
Checking dissolved solids prevents taste problems, scaling, and plant nutrient disorders. Whether you are a grower or a homeowner, this tool helps you monitor clean and healthy water every day.