Scientific, information & consultancy services for the food industry

Calculator for determining the number of survivors of a microbial population of known D-value following a heat treatment


To use the calculator add your data and press the submit button to obtain a prediction of the number of survivors.

Initial numbers of organism (mL) e.g. 100 CFU/mL
Temperature (°C) at which D was determined e.g.72 °C
D value (seconds)* e.g. 14 seconds
Duration of heat treatment (seconds) e.g. 15 seconds


* The D value should have been obtained or calculated at the same temperature used for thermal processing.

NOTE! The science and mathematics behind this calculator are described in the modeling exercise to investigate the survival of Mycobacterium avium subsp. paratuberculosis following HTST treatment of milk.

How to cite this article

Mullan, W.M.A. (2010) [On-line] UK: Available: Accessed: