Generation Time Calculator
Work backwards from two cell counts and the elapsed time to find doubling time and the specific growth rate of a culture.
Generation time (min)
20
Breakdown
- Generations observed
- 6
- Growth constant k (gen/hour)
- 3
- Specific rate μ (per hour)
- 2.08
Last updated:
FAQ
How do I calculate generation time from two counts?
n = log₂(N₂/N₁) gives the number of generations; dividing elapsed time by n gives the generation (doubling) time. Going from 10,000 to 640,000 cells in 2 hours is 6 generations, so each doubling took 20 minutes.
What is specific growth rate μ?
The natural-log slope of the growth curve: μ = ln(N₂) − ln(N₁) over time. It relates to doubling time as μ = ln 2 ÷ t_d. A 20-minute doubling corresponds to μ ≈ 2.08 per hour.
Does this work for cell cultures other than bacteria?
Yes — yeast, algae, and mammalian cells in log phase all follow the same exponential math. Only the typical doubling time differs: roughly 90 minutes for yeast, about 24 hours for mammalian lines.
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