Chemical Oxygen Demand (COD) Calculator

Find COD from a titration.

Blank titrant (mL)

Sample titrant (mL)

Titrant normality (N)

Sample volume (mL)

COD (mg/L) 320

Formula: COD = (blank − sample) × N × 8000 ÷ sample volume

Step-by-step with your numbers:

1. Values used:

2. Blank titrant = 20 mL

3. Sample titrant = 12 mL

4. Titrant normality = 0.1 N

5. Sample volume = 20 mL

7. COD = 320mg/L

Did we solve your problem today?

COD measures the oxygen needed to chemically oxidize organics in water.

The math behind it

COD (mg/L) = (blank − sample titrant) × normality × 8000 ÷ sample volume (mL).

(20 − 12) × 0.1 × 8000 ÷ 20 → 320 mg/L.

COD vs BOD?

COD oxidizes chemically (faster); BOD measures biological oxygen demand.