Biology Calculators
Log Reduction Calculator
Calculate log10 reduction and percentage reduction from initial and final microorganism counts (CFU).
Use this log reduction calculator to evaluate disinfectant or treatment efficacy from initial and final colony-forming units (CFU).
Formula used: log reduction = log10(initial CFU / final CFU).
Percentage reduction is computed as 100 × (initial CFU − final CFU) / initial CFU.
Inputs use scientific notation as mantissa × 10^exponent to keep very large CFU values manageable.
Initial CFU amount
× 103
CFUFinal CFU amount
× 101
CFULog reduction
Perecentage reduction
%