Free Cell Doubling Time Calculator
Calculate the doubling time of a cell culture from cell counts at two time points during exponential growth.
cells
cells
hours
Doubling Time (td)
8.00 hours
Growth Rate Constant (k)0.0866 1/h
Number of Generations3.00
Doubling Time (td) vs Time Elapsed (t)
Cell Doubling Time
During exponential growth, cells divide at a constant rate. The doubling time is the time required for the population to double.
Formulas
Growth rate: k = ln(Nt/N0) / t
Doubling time: td = ln(2) / k
Generations: n = ln(Nt/N0) / ln(2)
These formulas assume exponential (log-phase) growth without nutrient limitation or inhibition.
Example Calculation
A culture grows from 100,000 to 800,000 cells in 24 hours.
- 01k = ln(800000/100000) / 24 = ln(8) / 24 = 2.079 / 24 = 0.0866 h⁻¹
- 02td = ln(2) / 0.0866 = 0.693 / 0.0866 = 8.00 hours
- 03Generations = ln(8) / ln(2) = 3.00 doublings
Frequently Asked Questions
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