MAXScanner biology & lab calculator
Bacterial Growth & Doubling Time Calculator — Population, Generations & Growth Rate
Solve exponential bacterial growth forward or recover doubling time from initial and final population. See generations, fold change and specific growth rate in the same time unit used for the entered duration.
Results
Enter positive initial population and doubling time, plus elapsed time ≥ 0
Formula, example and assumptions
Forward: N=N₀×2^(t/td). Reverse: td=t×ln(2)/ln(N/N₀). Specific growth rate µ=ln(N/N₀)/t.
Starting with 1,000 cells and a 20-minute doubling time, 120 minutes is six generations and gives 64,000 cells under ideal exponential-growth assumptions.
- The model describes exponential/log-phase growth and does not include lag, nutrient limitation, stationary phase or death.
- Use the same time unit for elapsed time and doubling time; the reported growth rate is per entered time unit.
Frequently asked questions
Is generation time the same as doubling time?
For binary exponential growth they are commonly used for the time required for the population to double.
Can I calculate doubling time from two population measurements?
Yes. Enter initial population, final population and elapsed time in reverse mode; the calculator solves td=t·ln(2)/ln(N/N0).