EPA Method 21 Leak Rate Calculator

Convert screening values (ppmv) to leak rates (kg/h) using EPA correlations from Protocol for Equipment Leak Emission Estimates (EPA-453/R-95-017).

Methodological notice

These correlations estimate total organic compound (TOC) emission rates, not individual compound mass flows.
For petroleum industry correlations, TOC includes non-VOC compounds such as methane and ethane.
These are empirical power-law correlations derived from statistical data. Individual results carry significant uncertainty.
This calculator does not replace direct mass-flow measurement (e.g. bagging, Hi-Flow sampler).

Correlation family

EPA-453/R-95-017, Table 2-2

Equipment type

Reading type

Numeric value (ppmv)Pegged at 10,000 ppmvPegged at 100,000 ppmv

Screening value (SV) [ppmv]

Enter the Method 21 screening value in ppmv (parts per million by volume). Must be > 0.

Have questions about this calculator, or need help interpreting your screening results? Reach out — we're happy to help.

EPA Method 21 Leak Rate Calculator — ppmv to kg/h | Distran | Distran