Log Reduction Calculator
log₁₀(N₀/Nₜ) · Disinfection efficacy [citation:8]
Microbial Counts (CFU)
Count Comparison (Log Scale)
Log reduction = log₁₀(N₀ / Nₜ)
Percent reduction = (1 − Nₜ/N₀) × 100%
Results
Log reduction
—
Percent reduction
—%
Log to Percent Conversion
| Log Reduction | % Reduction | Survivor Ratio | Final Count (N) |
|---|---|---|---|
| 1-log | 90% | 1 in 10 | 100,000 |
| 2-log | 99% | 1 in 100 | 10,000 |
| 3-log | 99.9% | 1 in 1,000 | 1,000 |
| 4-log | 99.99% | 1 in 10,000 | 100 |
| 5-log | 99.999% | 1 in 100,000 | 10 |
| 6-log | 99.9999% | 1 in 1,000,000 | 1 |