DNA Replication Time Calculator

DNA Replication Time Calculator

DNA replication happens far faster than a single-point copying process would suggest, because replication proceeds simultaneously from multiple origin points using many active replication forks working in parallel.

Formula

Base Pairs Per Fork = Genome Size / Number of Forks
Replication Time = Base Pairs Per Fork / Polymerase Speed

Example

A 4.6 million bp genome (roughly E. coli genome size), polymerase speed of 1,000 bp/second, with 2 active replication forks:

BP Per Fork = 2,300,000 → Replication Time ≈ 38.3 minutes

Why More Forks Mean Faster Replication

More active replication forks working simultaneously proportionally reduces total replication time, similar to how multiple workers finish a job faster than one working alone - this is exactly why eukaryotic genomes, which are vastly larger than bacterial genomes, use thousands of simultaneous replication origins rather than the small handful used by bacteria, allowing replication to complete within a reasonable cell cycle timeframe despite the enormous genome size difference.

Polymerase Speed Varies by Organism

DNA polymerase speed itself differs by organism - bacterial replicative polymerases generally work considerably faster per fork than eukaryotic replicative polymerases, though eukaryotes compensate for their slower per-fork speed by using dramatically more simultaneous replication forks across their larger genomes.