How to Use This Calculator

Enter the volume of your water sample, the normality of the titrant used, and the volumes of titrant for both the sample and the blank. The COD will auto-update as you input data.

What Is This Calculator For?

This calculator helps determine the Chemical Oxygen Demand (COD) of a water sample, an essential parameter for measuring organic pollutants in wastewater treatment and environmental monitoring.

Formula Used

COD (mg/L) = ( (V_blank - V_sample) × N × 8000 ) / V_sample

Where:

• V_blank = volume of titrant for blank (mL)
• V_sample = volume of titrant for sample (mL)
• N = normality of titrant (N)
• 8000 = milliequivalent weight factor for oxygen

Example

If you used 20 mL of titrant for the blank, 15 mL for the sample, with a titrant normality of 0.1 N and a sample volume of 50 mL:

COD = ((20 - 15) × 0.1 × 8000) / 50 = 80 mg/L

References

For more information on this topic, visit Omni COD Calculator.