Interactive Calculator · 2026
Population Equivalent (PE) Calculator
Convert an organic pollution load into Population Equivalent — the number of people that would produce the same load. Enter the flow and BOD concentration of a wastewater stream to get its BOD load and equivalent population.
This facility's BOD load against reference population sizes
Your wastewater stream
Average daily wastewater flow.
Domestic sewage ≈ 250–350 mg/L; industrial streams vary widely.
The per-capita organic load that defines 1 PE — 60 g BOD/person/day is the standard European/CPCB figure.
How this is calculated
- BOD load = flow × BOD concentration ÷ 1000 = 100 × 300 ÷ 1000 = 30 kg/day.
- Population equivalent = BOD load × 1000 ÷ BOD per person = 30 × 1000 ÷ 60 = 500 PE.
- One PE is the organic load produced by one person per day — conventionally 60 g of BOD. It lets you compare industrial and domestic loads on a single human scale.
Indicative figures for concept planning. Population equivalent based on BOD is the most common basis; some standards also define PE on COD or nitrogen. Confirm the basis your regulator requires.
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