Free · Laboratory and chemistry models

Dissolved-Ion Sum & Conductivity TDS Scenario

Calculate dissolved-ion sum & conductivity tds scenario with the retained input modes, unit choices and stated arithmetic assumptions.

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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

At 35.5 mg/L chloride and 23 mg/L sodium using the retained rounded molar masses, each contributes 1 mEq/L and the modeled ion-mass subtotal is 58.5 mg/L.

Ion total=sum of entered ion masses per liter; conductivity estimate=k×EC; charge balance=100×|cation equivalents−anion equivalents|/(sum of equivalents).

Worked example

Enter these known values and leave the other values blank.

Chloride (Cl⁻)
35.5 mg/L
Sodium (Na⁺)
23 mg/L
Total dissolved solids (TDS)
58.5 mg/L
TDS anions
35.5 mg/L
TDS cations
23 mg/L

Assumptions and limitations

  • The analysis mode sums only the listed dissolved ions; unlisted ions and dissolved nonionic material are omitted. Zero defaults mean assumed absence, not laboratory confirmation.
  • Molar and equivalent quantities use captured rounded formula masses and ionic charges. The conductivity mode uses a supplied empirical factor and temperature-specific conductivity.
  • A charge imbalance is a data-quality comparison, not a drinking-water safety determination. The empirical conductivity conversion does not identify individual contaminants.

Common questions

What does this result represent?

The analysis mode sums only the listed dissolved ions; unlisted ions and dissolved nonionic material are omitted. Zero defaults mean assumed absence, not laboratory confirmation.

Can I solve for another quantity?

Enter the known quantities and clear the unknown where an inverse relationship is available. Selection presets remain separate from measurements you supply; use locks to retain known inputs.

References

Bookify enforces finite physical or discrete inputs for this model and detects the stated selected-scenario relationships without changing the captured arithmetic graph. Molar ion sums divide each mass concentration by its rounded formula mass once. Charge multiplies only equivalent concentrations; this removes the captured charge-squared error in the two molar presentation outputs.

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