Log Reduction Calculator

Calculate log reduction values for microbial inactivation, sterilization efficiency, and disinfection effectiveness in laboratory and industrial applications.

Microbial Count Data

CFU/mL

Number of microorganisms before treatment

CFU/mL

Number of microorganisms after treatment

Method used for microbial reduction

Duration of treatment

Temperature during treatment (if applicable)

Log Reduction Results

Enter microbial count data to calculate log reduction

Log Reduction Guidelines

Log Reduction Levels

  • • 1-log: 90% reduction (10-fold)
  • • 2-log: 99% reduction (100-fold)
  • • 3-log: 99.9% reduction (1,000-fold)
  • • 4-log: 99.99% reduction (10,000-fold)
  • • 5-log: 99.999% reduction (100,000-fold)

Applications

  • • Water treatment: 3-6 log reduction
  • • Food processing: 5-7 log reduction
  • • Medical devices: 6-12 log reduction
  • • Pharmaceutical: 6+ log reduction