Doubling Time Calculator
Calculate population doubling time from growth rate or observed population changes.
Calculation Method
Doubling Time Formula
td = ln(2) / r = 0.693 / r
Rule of 70: td ≈ 70 / (r × 100)
Doubling Time
19.80 hours
Time for population to double
Growth Statistics
Growth Rate (r)0.0350 per hours
Rule of 70 Estimate20.00 hours
Growth per hours3.56%
Doublings in 24 hours1.21
Common Doubling Times
E. coli (optimal)20 min
Yeast (S. cerevisiae)90 min
Mammalian cells24 hours
Human population~50 years
Cancer cells1-4 days