Calculate the average doubling time implied by two positive qPCR target quantity measurements and the elapsed time between them. The tool converts the observed fold change into a number of doublings, then reports minutes per doubling and doublings per hour. Use it for an exponential-growth approximation when both measurements refer to the same target and use comparable units.
Doublings = log₂(Final ÷ Initial)
Doubling time = Elapsed time ÷ Doublings
A shorter doubling time indicates faster exponential increase over the observed interval.
The estimate assumes exponential behavior throughout the interval. It does not correct for qPCR efficiency, inhibition, plateau effects, extraction loss, or assay calibration.
A quantity rising from 1,000 to 16,000 copies in 120 minutes increases 16-fold, equal to 4 doublings. The doubling time is 120 ÷ 4 = 30 minutes, or 2 doublings per hour.
A positive doubling time requires observed growth; equal or lower values do not describe doubling.
Yes, if both positive measurements are comparable and proportional to quantity over the interval.
No. It is a direct exponential-growth estimate from the two quantities entered.
Each doubling multiplies quantity by two, and 2 to the fourth power equals 16.
The field is in minutes. Convert hours to minutes before entering the interval.
| Variable | Meaning |
|---|---|
| N₀ | Initial positive quantity |
| Nₜ | Final quantity |
| t | Elapsed minutes |
| g | Average minutes per doubling |