Cell Doubling Time Calculator
Calculate cell doubling time (td) and specific growth rate (μ) from cell counts. Predict future cell populations. Covers HeLa, MCF-7, E. coli, and other common cell lines.
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Doubling Time (td)
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Specific Growth Rate (μ) —
Number of Doublings —
Extended More scenarios, charts & detailed breakdown ▾
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Doubling Time td
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Growth Rate μ —
Doublings Occurred —
Professional Full parameters & maximum detail ▾
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cm²
cells/cm²
N at Total Time
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N at End of Lag Phase —
Doublings in Log Phase —
Final Density —
Passage Recommended —
How to Use This Calculator
- Enter the initial cell count (N₀) and final cell count (N).
- Enter the time elapsed (hours) between the two counts.
- Results show doubling time, specific growth rate μ, and number of doublings.
- Use From Growth Rate to convert μ directly to td.
- Use Predict Future Population to extrapolate forward in time.
Formula
td = t × ln(2) / ln(N/N₀)
Specific growth rate: μ = ln(N/N₀) / t
Future population: N(t) = N₀ × 2^(t/td)
Example
Example: N₀ = 100,000 cells, N = 800,000 cells after 24 h. td = 24 × 0.693 / ln(8) = 24 × 0.693 / 2.079 = 8 h. Three doublings occurred (100k → 800k).
Frequently Asked Questions
- Cell doubling time (td) is the time required for a cell population to double in number during exponential growth. It is calculated as td = t × ln(2) / ln(N/N₀), where t is elapsed time and N/N₀ is the growth ratio.
- Approximate doubling times: HeLa ~24 h, MCF-7 ~29 h, HEK293 ~24 h, CHO ~22 h, Jurkat ~24 h. E. coli ~20 min under optimal conditions, S. cerevisiae (yeast) ~90 min, doubling times slow markedly at high passage number.
- Cell cultures pass through four phases: (1) Lag phase — cells adapt to the new environment; (2) Log (exponential) phase — rapid doubling at constant rate; (3) Stationary phase — growth slows as nutrients deplete; (4) Death phase — cells die faster than they divide.
- The specific growth rate μ (h⁻¹) relates to doubling time td by: td = ln(2) / μ. A fast-growing E. coli at μ = 0.035 h⁻¹ has td ≈ 20 min; a mammalian cell at μ = 0.029 h⁻¹ has td ≈ 24 h.
- Most adherent cell lines should be passaged at 70-85% confluence to maintain healthy, exponentially growing cells. Allowing cells to reach 100% confluence causes contact inhibition and may alter gene expression. Passage number should be kept below ~30 for most experimental work.
Related Calculators
Sources & References (5) ▾
- ATCC Cell Line Doubling Times and Culture Conditions — ATCC
- Cold Spring Harbor Protocols — Cell Culture Techniques — Cold Spring Harbor Laboratory Press
- NCBI Bookshelf — Molecular Cell Biology, Chapter 1 — NCBI / W.H. Freeman
- Sigma-Aldrich Cell Culture Manual — Growth Kinetics — MilliporeSigma
- Lehninger Principles of Biochemistry — Cell Biology Appendix — Macmillan