Update Time Estimator
Estimate total time to download and install a batch of system package updates.
About Update Time Estimator
Total package update duration splits into two largely sequential phases: downloading all package archives, bounded by available bandwidth, and installing each package, which involves unpacking files, running pre/post-install scripts, and updating package manager metadata — a fixed per-package cost regardless of network speed. Summing download time (total download size divided by effective bandwidth) and install time (packages multiplied by average install time each) gives a realistic estimate for planning maintenance windows or automated patching schedules.
Formulas
Download time
download_time = (packages × avg_size_MB) / (bandwidth_Mbps / 8)
- n
- package count
- s
- average download size in MB
- b
- bandwidth in Mbps
Total update time
total = download_time + (packages × avg_install_time)
- t_i
- average install time per package
Worked example
With the default values below, Update Time Estimator returns Total Update Time of 4.45. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Number of Packages to Updateminimum 0
- 85
- Average Download Size per Packageminimum 0 MB
- 8 MB
- Download Bandwidthminimum 0.1 Mbps
- 100 Mbps
- Average Install Time per Packageminimum 0 seconds
- 2.5 seconds
Results
- Total Update Time
- 4.45 minutes
- Download Time
- 54.4 seconds
- Install Time
- 212.5 seconds
- Total Download Size
- 680.0 MB
Step by step
- 1Values used
- 2Download time
- 3Total update time
- 4Total Update Time= 4.45 minutes
- 5Download Time= 54.4 seconds
- 6Install Time= 212.5 seconds
- 7Total Download Size= 680.0 MB
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
Why is install time often the larger component for many small packages?
Each package incurs fixed overhead — extracting archive contents, running maintainer scripts, updating the package database — independent of the package's download size, so a system with hundreds of small packages to update can spend more total time in installation than in downloading, even on a modest connection.
Does this account for dependency resolution time?
No — this estimates only download and install time for the packages themselves. Dependency resolution (calculating which packages need updating and in what order) typically adds a smaller, roughly fixed overhead at the start of the update process that varies by package manager and repository metadata size.
How can I speed up package updates on a fleet of servers?
Run a local package mirror or caching proxy (apt-cacher-ng, a local yum/dnf repo) so downloads happen at LAN speed instead of over the internet for every host, and consider parallelizing installs across independent packages where the package manager supports it.