Ion Exchange Capacity Calculator

Work out ion exchange capacity instantly with clear inputs, formula shown and shareable results.

About Ion Exchange Capacity Calculator

Total exchange capacity is a fixed property of the resin, typically 1.8-2.2 eq/L for strong acid cation resin. Operating capacity is only 40-70% of it because regeneration is never complete and leakage rises before full exhaustion. Throughput is operating capacity divided by the influent ionic load.

Formulas

Capacity

Total equivalents = resin volume (L) x total capacity (eq/L); operating = total x efficiency

Throughput

Throughput (m3) = operating equivalents / influent load (eq/m3)

Worked example

With the default values below, Ion Exchange Capacity Calculator returns Throughput Per Cycle of 240.000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Resin Volumeminimum 0 m3: 1 m3
Total Exchange Capacityminimum 0 eq/L: 2 eq/L
Operating Efficiencyaccepts 0–100 %: 60 %
Influent Ionic Loadminimum 0 meq/L: 5 meq/L

Results

Throughput Per Cycle: 240.000
Operating Capacity: 1,200.00
Total Capacity: 2,000.00
Bed Volumes Treated: 240.00

Step by step

1Values used
2Capacity
3Throughput
4Throughput Per Cycle= 240.000
5Operating Capacity= 1,200.00
6Total Capacity= 2,000.00
7Bed Volumes Treated= 240.00

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why express load in milliequivalents?

Because ion exchange trades charge, not mass. A divalent calcium ion occupies two sites, so loads must be converted to equivalents before comparing with resin capacity.

What causes capacity loss over time?

Organic fouling, iron and manganese precipitation, oxidative attack from chlorine, and physical bead breakage. Regular capacity testing shows when replacement is due.